ASTM D7258-23

Standard Specification for Polymeric Piles

ABSTRACT
This specification establishes the physical and performance requirements for round and rectangular cross-section polymeric piles in axial and lateral load-bearing applications including, by not limited to, marine, waterfront, and corrosive environments. It does not apply to individual polymeric pile products, sheet piles, and other mechanically connected polymeric pile products using inter-locking systems. Covered here are six types of polymeric piles that are fabricated from materials that may be virgin, recycled, or both, as long as the finished product meets all of the criteria specified herein. These types are: Type I, polymeric only; Type II, polymeric with reinforcement in the form of chopped, milled or continuous fiber or mineral; Type III, polymeric with reinforcement in the form of metallic bars, cages, or shapes; Type IV, polymeric with reinforcement in the form of non-metallic bars or cages; Type V, polymeric composite tube with a concrete core; and Type VI, any other polymeric piling meeting the requirements stated herein and not otherwise described by Types I through V. The polymeric tiles shall adhere to specified physical attributes such as size, cross-sectional shape, length, straightness, placement of reinforcement, and surface conditions. The performance requirements which pile specimens shall conform to include creep rupture, serviceability, flexural properties, shear strength, bearing strength, design flexural stiffness, energy absorption, compressive strength, combined stresses, dimensional stability (thermal expansion), hygrothermal cycling, and flame spread index.
SCOPE
1.1 This specification addresses the use of round and rectangular cross-section polymeric piles in axial and lateral load-bearing applications, including but not limited to marine, waterfront, and corrosive environments.  
1.2 This specification is only applicable to individual polymeric pile products. Sheet pile and other mechanically connected polymeric pile products using inter-locking systems, are not part of this specification.  
1.3 The piling products considered herein are characterized by the use of polymers, whereby (1) the pile strength or stiffness requires the inclusion of the polymer, or (2) a minimum of fifty percent (50 %) of the weight or volume is derived from the polymer. The type classifications of polymeric piles described in Section 4 show how they can be reinforced by composite design for increased stiffness or strength.  
1.4 This specification covers polymeric piles fabricated from materials that are virgin, recycled, or both, as long as the finished product meets all of the criteria specified herein. Diverse types and combinations of inorganic filler systems are permitted in the manufacturing of polymeric piling products. Inorganic fillers include such materials as talc, mica, silica, wollastonite, calcium carbonate, etc. Pilings are often placed in service where they will be subjected to continuous damp or wet exposure conditions. Due to concerns of water sensitivity and possible affects on mechanical properties in such service conditions, organic fillers, including lignocellulosic materials such as those made or derived from wood, wood flour, flax shive, rice hulls, wheat straw, and combinations thereof, are not permitted in the manufacturing of polymeric piling products.  
1.5 The values are stated in inch-pound units as these are currently the most common units used by the construction industry.  
1.6 Polymeric piles under this specification are designed using design stresses determined in accordance with Test Methods D6108, D6109, and D6112 and procedures contained within this specification unless otherwise specified.  
1.7 Although in some instances it will be an important component of the pile design, frictional properties are currently beyond the scope of this document.  
1.8 Criteria for design are included as part of this specification for polymeric piles. Certain Types and...

General Information

• Status: Published
• Publication Date: 31-Jan-2023
• ICS: 83.140.99 - Other rubber and plastics products
• Technical Committee: D20 - Plastics
• Drafting Committee: D20.20 - Plastic Lumber

Relations

• Refers: ASTM D6108-24 - Standard Test Method for Compressive Properties of Plastic Lumber and Shapes
• Effective Date: 01-Feb-2024
• Refers: ASTM D883-24 - Standard Terminology Relating to Plastics
• Effective Date: 01-Feb-2024
• Refers: ASTM D6109-24 - Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastic Lumber and Related Products
• Effective Date: 01-Feb-2024
• Refers: ASTM E176-24 - Standard Terminology of Fire Standards
• Effective Date: 01-Jan-2024
• Refers: ASTM E84-23d - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Dec-2023
• Refers: ASTM D6112-23 - Standard Test Methods for Compressive and Flexural Creep and Creep-Rupture of Plastic Lumber and Shapes
• Effective Date: 01-Nov-2023
• Refers: ASTM D883-23 - Standard Terminology Relating to Plastics
• Effective Date: 01-Nov-2023
• Refers: ASTM E84-23c - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Sep-2023
• Refers: ASTM D883-20 - Standard Terminology Relating to Plastics
• Effective Date: 01-Jan-2020
• Refers: ASTM D883-19c - Standard Terminology Relating to Plastics
• Effective Date: 01-Aug-2019
• Refers: ASTM E84-19b - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 01-Jul-2019
• Refers: ASTM D6108-19 - Standard Test Method for Compressive Properties of Plastic Lumber and Shapes
• Effective Date: 01-May-2019
• Refers: ASTM D883-19a - Standard Terminology Relating to Plastics
• Effective Date: 15-Apr-2019
• Refers: ASTM E84-19a - Standard Test Method for Surface Burning Characteristics of Building Materials
• Effective Date: 15-Apr-2019
• Refers: ASTM D6109-19 - Standard Test Methods for Flexural Properties of Unreinforced and Reinforced Plastic Lumber and Related Products
• Effective Date: 01-Apr-2019

Overview

ASTM D7258-23: Standard Specification for Polymeric Piles establishes rigorous requirements for round and rectangular cross-section polymeric piles used in axial and lateral load-bearing applications. This standard, developed by ASTM International, is particularly relevant for polymeric piles utilized in marine, waterfront, and corrosive environments where durability and resistance to environmental factors are critical. The specification covers six distinct types of polymeric piles, constructed from virgin, recycled, or mixed polymeric materials, with or without various types of reinforcements.

Key Topics

• Material Classifications:
  The standard classifies polymeric piles as follows:

  • Type I: Polymeric only
  • Type II: Polymeric with fiber or mineral reinforcements
  • Type III: Polymeric with metallic bars, cages, or shapes
  • Type IV: Polymeric with non-metallic bars or cages
  • Type V: Polymeric composite tube with concrete core
  • Type VI: Other polymeric pile types meeting standard requirements

• Physical and Performance Requirements:
  Polymeric pile products must meet specific criteria related to:

  • Size, shape, and straightness
  • Placement and type of reinforcement
  • Surface condition (limits on imperfections)
  • Dimensional tolerances and stability

• Mechanical Properties and Testing:

  • Creep rupture
  • Flexural and shear strength
  • Bearing and compressive strength
  • Design flexural stiffness
  • Energy absorption capacity
  • Combined stresses
  • Dimensional stability under thermal and hygrothermal cycling
  • Flame spread index

• Exclusions:
  This specification does not cover sheet pile, mechanically connected piles using interlocking systems, or products using organic fillers like wood or lignocellulosic materials, due to water sensitivity concerns.

Applications

ASTM D7258-23 is vital for engineers, designers, and manufacturers involved in:

• Marine and Waterfront Construction:
  Polymeric piles offer resistance to corrosion, rot, and marine organisms, making them ideal for docks, piers, wharves, jetties, and fenders in both saltwater and freshwater locations.

• Load-Bearing Structures:
  Used as axial load-bearing piles for foundation support, or as lateral load-bearing piles for absorbing and distributing horizontal forces, such as in waterfront protection structures and energy-absorbing fender systems.

• Corrosive or Harsh Environments:
  Beneficial for applications exposed to chemicals, de-icing salts, or biologically aggressive environments where traditional materials like steel or timber may deteriorate.

• Sustainable Construction:
  Polymeric piles made from recycled materials provide environmentally friendly solutions conforming to modern sustainability goals, without compromising mechanical performance.

Related Standards

Several ASTM and external standards are referenced within ASTM D7258-23 for testing and classification:

• ASTM D6108: Testing compressive properties of plastic lumber and shapes
• ASTM D6109: Testing flexural properties of unreinforced and reinforced plastic lumber
• ASTM D6112: Testing compressive and flexural creep in plastic lumber
• ASTM D6341: Determining linear coefficient of thermal expansion
• ASTM E84: Surface burning characteristics (flame spread index)
• ASCE 7: Minimum Design Loads for Buildings and Other Structures
• AASHTO HB-13: Standard Specification for Highway Bridges

Practical Value

The ASTM D7258-23 standard enhances project quality, safety, and durability in environments demanding high performance from pile foundations. By adhering to this specification:

• Designers and Engineers can ensure structural reliability and select suitable polymeric pile types for varied project needs.
• Manufacturers can standardize production for global markets, guaranteeing product consistency and code compliance.
• Construction Professionals can specify safe, sustainable, and long-lasting polymeric pile products for challenging environments.

Implementing ASTM D7258-23 supports innovation in the use of advanced materials in infrastructure while addressing evolving regulatory and environmental requirements.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7258 − 23
Standard Specification for
Polymeric Piles
This standard is issued under the fixed designation D7258; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* Methods D6108, D6109, and D6112 and procedures contained
within this specification unless otherwise specified.
1.1 This specification addresses the use of round and rect-
angular cross-section polymeric piles in axial and lateral 1.7 Although in some instances it will be an important
load-bearing applications, including but not limited to marine, component of the pile design, frictional properties are currently
waterfront, and corrosive environments. beyond the scope of this document.
1.2 This specification is only applicable to individual poly- 1.8 Criteria for design are included as part of this specifi-
meric pile products. Sheet pile and other mechanically con- cation for polymeric piles. Certain Types and sizes of poly-
nected polymeric pile products using inter-locking systems, are meric piles will be better suited for some applications than
not part of this specification. others. Polymeric piles designed and manufactured under the
different Type classifications as defined within this specifica-
1.3 The piling products considered herein are characterized
tion will, as a whole, exhibit a wide-range of mechanical
by the use of polymers, whereby (1) the pile strength or
properties. For example, a 10-in. diameter Type II, chopped
stiffness requires the inclusion of the polymer, or (2) a
glass fiber reinforced high-density polyethylene (HDPE) pile
minimum of fifty percent (50 %) of the weight or volume is
will likely have an apparent stiffness much different than a
derived from the polymer. The type classifications of poly-
10-in. diameter Type V, glass fiber reinforced composite tube
meric piles described in Section 4 show how they can be
filled with concrete. Similarly, the ultimate moment capacity of
reinforced by composite design for increased stiffness or
these two example piles will also likely be significantly
strength.
different from each other. Use of a licensed Professional
1.4 This specification covers polymeric piles fabricated
Engineer is, therefore, highly recommended for designing and
from materials that are virgin, recycled, or both, as long as the
selecting polymeric piles in accordance with this specification.
finished product meets all of the criteria specified herein.
1.9 This standard does not purport to address all of the
Diverse types and combinations of inorganic filler systems are
safety concerns, if any, associated with its use. It is the
permitted in the manufacturing of polymeric piling products.
responsibility of the user of this standard to establish appro-
Inorganic fillers include such materials as talc, mica, silica,
priate safety, health, and environmental practices and deter-
wollastonite, calcium carbonate, etc. Pilings are often placed in
mine the applicability of regulatory limitations prior to use.
service where they will be subjected to continuous damp or wet
exposure conditions. Due to concerns of water sensitivity and NOTE 1—There is no known ISO equivalent to this specification.
possible affects on mechanical properties in such service
1.10 This international standard was developed in accor-
conditions, organic fillers, including lignocellulosic materials
dance with internationally recognized principles on standard-
such as those made or derived from wood, wood flour, flax
ization established in the Decision on Principles for the
shive, rice hulls, wheat straw, and combinations thereof, are not
Development of International Standards, Guides and Recom-
permitted in the manufacturing of polymeric piling products.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.5 The values are stated in inch-pound units as these are
currently the most common units used by the construction
2. Referenced Documents
industry.
2.1 ASTM Standards:
1.6 Polymeric piles under this specification are designed
D883 Terminology Relating to Plastics
using design stresses determined in accordance with Test
D1141 Practice for Preparation of Substitute Ocean Water
This specification is under the jurisdiction of ASTM Committee D20 on
Plastics and is the direct responsibility of Subcommittee D20.20 on Plastic Lumber. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Feb. 1, 2023. Published February 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 2009. Last previous edition approved in 2017 as D7258 – 17. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D7258-23. the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7258 − 23
D2344/D2344M Test Method for Short-Beam Strength of 3.2 Definitions of Terms Specific to This Standard:
Polymer Matrix Composite Materials and Their Laminates 3.2.1 axial load-bearing pile, n—a vertical or battered
D2915 Practice for Sampling and Data-Analysis for Struc- member driven into the ground to help support a load of any
tural Wood and Wood-Based Products structure bearing upon it. Axial load-bearing piles are com-
D5033 Guide for Development of ASTM Standards Relating monly divided into two kinds; point-bearing (end-bearing) and
to Recycling and Use of Recycled Plastics (Withdrawn friction. A point-bearing pile derives practically all its support
2007) from the rock or soils near the point and much less from
D6108 Test Method for Compressive Properties of Plastic contact with soil along the pile shaft. A friction pile derives its
Lumber and Shapes support principally from the soil along the pile shaft through
D6109 Test Methods for Flexural Properties of Unreinforced the development of shearing resistance between the soil and the
and Reinforced Plastic Lumber and Related Products pile.
D6112 Test Methods for Compressive and Flexural Creep
3.2.2 lateral load-bearing pile, n—a vertical or battered
and Creep-Rupture of Plastic Lumber and Shapes
member driven into the ground to resist lateral loads imposed
D6341 Test Method for Determination of the Linear Coef-
upon it or a structure. A common application for a lateral
ficient of Thermal Expansion of Plastic Lumber and
load-bearing pile is to absorb lateral forces at points of impact
Plastic Lumber Shapes Between –30 and 140°F (–34.4
and dissipate them horizontally into a structure and/or soil
and 60°C)
stratum. A fender pile is an example of a lateral load-bearing
D6662 Specification for Polyolefin-Based Plastic Lumber
pile.
Decking Boards
3.2.3 combined axial and lateral load-bearing pile, n—a
E84 Test Method for Surface Burning Characteristics of
vertical or battered member driven into the ground to resist
Building Materials
both axial and lateral loads or applied external forces imposed
E176 Terminology of Fire Standards
upon it. Combined axial and lateral load-bearing piles are
2.2 Other Documents:
commonly divided into two kinds; point-bearing (end-bearing)
ASCE 7 Minimum Design Loads for Buildings and Other
and friction. A point-bearing pile derives practically all its
Structures
support from the rock or soils near the point and much less
AASHTO GSDPB-1 Standard Specification for Design of
from contact with soil along the pile shaft. A friction pile
Pedestrian Bridges
derives its support principally from the soil along the pile shaft
AASHTO HB-13 Standard Specification for Highway
through the development of shearing resistance between the
Bridges
soil and the pile.
Department of Defense Unified Facility Criteria UFC 4-152-
01 Design: Piers and Wharves, Naval Facilities Engineer-
4. Classification
ing Command, Washington DC
4.1 Polymeric Piles contained in this specification are clas-
sified as following six (6) types:
3. Terminology
4.1.1 Type I—Polymeric only.
3.1 Definitions of Terms:
4.1.2 Type II—Polymeric with reinforcement in the form of
3.1.1 For definitions of terms used in this specification
chopped, milled or continuous fiber or mineral.
associated with plastics issues refer to the terminology con-
4.1.3 Type III—Polymeric with reinforcement in the form of
tained in Terminology D883. For definitions of terms used in
metallic bars, cages, or shapes.
this specification and associated with fire issues refer to the
4.1.4 Type IV—Polymeric with reinforcement in the form of
terminology contained in Terminology E176. Additional defi-
non-metallic bars or cages.
nitions of terms applying to this specification appear in Guide
4.1.5 Type V—Polymeric composite tube with a concrete
D5033.
core.
3.1.2 plastic lumber, n—a manufactured product made pri-
4.1.6 Type VI—Any other polymeric piling meeting the
marily from plastic materials (filled or unfilled), typically used
requirements in 1.3 and not otherwise described by Types I
as a building material for purposes similar to those of tradi-
through V above.
tional lumber, which is usually rectangular in cross-section.
D883
5. Ordering Information
3.1.2.1 Discussion—Plastic lumber is typically supplied in
5.1 The purchaser shall state whether this specification is to
sizes similar to those of traditional lumber board, timber and
be used, select the preferred options permitted herein, and
dimension lumber; however the tolerances for plastic lumber
include the following information in the invitation to bid and
and for traditional lumber are not necessarily the same. D883
purchase order:
5.1.1 Title, number and date of this specification,
3 5.1.2 Type and composition,
The last approved version of this historical standard is referenced on www.ast-
5.1.3 Percent recycled content (if requested),
m.org.
Available from American Society of Civil Engineers (ASCE), 1801 Alexander
5.1.4 Flame spread index, if applicable,
Bell Dr., Reston, VA 20191, http://www.asce.org.
5.1.5 Color,
Available from American Association of State Highway and Transportation
5.1.6 Quantity in linear feet (meters), and minimum length
Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
http://www.transportation.org. without splices,
D7258 − 23
5.1.7 Cross-sectional dimensions, 8.3 Axial load-bearing piles shall have no more than 1 in.
5.1.8 Performance requirements including flexural strength, (24 mm) bow or bend in 20 ft (6.5 m) of length.
axial strength, and stiffness,
8.4 Straightness as defined in 8.2 and 8.3 shall be inter-
5.1.9 Required accessories including pile tips, splices and
preted as the as-built straightness.
driving caps,
5.1.10 Special handling, packing, or shipping requirements,
9. Placement of Reinforcement for Pile Types III and IV
5.1.11 Marking, if other than specified, and
only
5.1.12 Shop drawings and submittals.
9.1 Longitudinal reinforcement shall remain within 5 % of
the specified radial location as measured from centroid of the
6. Tolerances
cross-section of the pile.
6.1 Sizes:
9.2 Longitudinal reinforcement shall not twist more than 5°
6.1.1 Circular Piles:
over any 20 ft (6.1 m) section of the pile.
6.1.1.1 Maximum deviation from a circular cross section
shall be:
10. Surface Condition
b 5 0.98a (1)
10.1 The pile surface will typically exhibit some roughness
or corrugations due to manufacturing processes. However, the
where:
piles shall not have depressions or projections greater than ⁄2
2a = major oval diameter, and
in. (13 mm) and the total surface area of any such depressions
2b = minor oval diameter.
2 2
or projections shall not be greater than 9 in. (58 cm ).
(1) For example, for 13 in. (330 mm) major diameter pile,
maximum allowable difference between major and minor
10.2 The surface of the pile shall contain no cracks or splits,
diameter would be 0.26 in. (7 mm).
in any orientation.
6.1.1.2 Diameter—Tolerance against specified diameter =
11. Performance Requirements
63 %.
11.1 The cross-sectional dimensions of piles will be deter-
6.1.2 Rectangular Piles:
mined on the basis of the ability to perform satisfactorily under
6.1.2.1 Squareness of Piles—Measurements of the two op-
the physical loading and environmental conditions imposed as
posing diagonals shall not differ by more than 3 %, calculated
well as the energy absorption properties desired. Testing
with the smaller diagonal denominator.
methods and procedures for analysis of results to define
6.1.2.2 Dimensions shall not vary from specified dimension
allowable values for the design of plastic piles are given below.
by more than 3 %.
6.1.3 Cross-Section—All piles, regardless of cross sectional
11.2 Load Combinations—Polymeric piles subject to mul-
shape shall remain consistent in cross-sectional area along the
tiple load types shall be checked for all applicable load
length of the pile, except that a tolerance of 66 % is permitted
combinations. Load factors and load reductions shall be
against the nominal or specified area at any location along the
determined in accordance with the applicable code or ASCE 7.
length of pile.
Where allowed by the applicable code or ASCE 7, allowable
6.1.4 Each pile shall be measured at a minimum of three
stress increases are permitted. Each load type in combination
locations at quarter points along its length, prior to shipment, to
shall be divided by the load duration factor corresponding to
confirm compliance with this section.
the load type’s duration. See A2.1 for the procedure to
6.1.5 Pile head tolerance from the plane perpendicular to the
determine the load duration factor. A sample calculation of the
longitudinal axis of the pile shall be ⁄4 in. (6 mm) in 12 in. (305
load duration factor is provided in Appendix X1.
mm) but not more than ⁄2 in. over the whole pile length (12
NOTE 2—Applicable codes vary depending upon location and usage.
Relevant codes may include, but are not limited to, American Association
mm).
of State Highway and Transportation Officials (AASHTO) HB-13, Stan-
dard Specification for Highway Bridges, AASHTO GSDPB-1, Standard
7. Lengths
Specification for Design of Pedestrian Bridges, or Department of Defense
Unified Facility Criteria (UFC) 4-152-01 Design: Piers and Wharves.
7.1 All piles shall be furnished in lengths specified, except
that tolerances shall be plus 1 ft (0.3 m), minus 0 in. (0 mm)
11.3 Design Strength:
corrected to 73°F, and
11.3.1 All piles shall be designed such that for all load
combinations:
7.2 Piles 41 ft or longer—plus 2 ft (0.6 m), minus 0 in (0
mm) corrected to 73°F.
f # F ' × C (2)
a n D
where:
8. Straightness
f = total applied stress in each combination (psi),
a
8.1 A straight line from the center of the head to the center
F ' = allowable stress as calculated in 11.7.3, 11.8.2, 11.9.2,
n
of the tip shall lie entirely within the body of the pile when the
11.9.3, or 11.12.2 (psi), and
pile is vertically suspended from the head.
C = Load Duration Factor for the material and considered
D
8.2 Lateral load-bearing piles shall be free of short crooks
load duration. Derivation of C is explained in Annex
D
that deviate more than 2 ⁄2 in. (64 mm) from straightness in any A2.
20 ft (1.5 m) length. See Fig. 1. NOTE 3—Results from testing of plastic lumber decking boards after
D7258 − 23
FIG. 1 Measurement of Short Crook N.T.S.
eleven years of outdoor exposure have shown that the boards had
11.4.1.3 At least one test is performed on specimens with a
discolored and faded, but that both strength and stiffness were basically
width or diameter greater than that of the product whose
unchanged. Similar results are expected with polymeric piles made with
properties are being interpolated.
similar materials. Introduction of carbon black and other additives can
significantly reduce ultraviolet light degradation of polymers. Further 11.4.1.4 At least one test is performed on specimens with a
details of this testing and results are given in Appendix X3 in Specification
width or diameter less than that of the product whose properties
D6662.
are being interpolated.
11.4 Interpolation of Mechanical Properties:
11.4.1.5 For rectangular piles all specimens have the same
11.4.1 Interpolation of mechanical properties of a polymeric
thickness.
pile from other pile test data is permitted if the test results
11.5 Creep Rupture:
verify a logical progression of properties and the following
conditions are met: 11.5.1 Creep rupture tests shall be performed for the in-
11.4.1.1 All specimens have the same and material compo- tended use (that is, flexural test for a flexural member,
sition. compression test for a compression member) in accordance
11.4.1.2 Three or more tests are performed on specimens with the procedures outlined in Test Methods D6112 including
with varying width or diameter. the following modifications:
D7258 − 23
11.5.1.1 The stress in the outer fiber, as indicated in subsec- where:
tion 12.3.1 of Test Methods D6112, in flexural creep tests shall
F = the base flexural stress value at 23°C (73.4°F) for
b
be modified to be calculated as follows:
normal duration loading (ten-year duration), (psi) as
defined as follows:
M
F 5 (3)
S
F 5 F ·β # F (6)
b bt cr
where:
where:
F = the stress in the outer fiber throughout load span, (psi),
F = the nonparametric 5 % lower tolerance limit at 75 %
bt
S = section modulus (in. ), and
confidence of the flexural stress at 3 % outer fiber
M = Bending Moment.
strain (or failure if 3 % strain cannot be reached)
11.5.1.2 The maximum strain, as indicated in subsection determined from flexure tests conducted in accor-
12.3.2 of Test Methods D6112, in the outer fiber at the dance with 11.7.1 (psi). Statistical calculations shall
mid-span is calculated as follows: be in accordance with Practice D2915.
F = ultimate creep rupture stress for flexure calculated in
2 cr
ξ 5 9.39·y·Δ/L (4)
accordance with 11.5, (psi),
where: β = stress-time factor to convert the test value, F , to a ten
bt
year normal duration value. This value shall be
y = distance from the outer fiber to the centroid of the
determined in accordance with Annex A1,
section, (in.),
FS = factor of safety = 2.0,
Δ = maximum deflection at mid-span, (in.), and
C = temperature factor for flexure determined in accor-
L = support span, (in.).
TF
dance with Annex A3, and
11.5.2 F shall be the stress required to cause creep rupture
cr
C = beam stability factor defined as follows:
L
in ten years determined from the creep rupture curve calculated
in Test Methods D6112. 11.7.3.1 C = 1.0 for a beam with a thickness greater than or
L
equal to its depth (t ≥ d), round sections, or a beam with full
11.6 Serviceability:
lateral support. For all other beams:
11.6.1 The maximum ten-year strain in any member shall
not exceed 0.03 (3 %).
c·C ·π E' I G' J
b y
C 5 ·Œ # 1.0 (7)
S D
L
I ·F ·L ~1 2 I /I !
NOTE 4—Applicable codes or project specific requirements may require x b u y x
deflection limits that result in a maximum strain of less than 0.03.
where:
11.6.2 Deflection shall be calculated using the apparent
c = distance from outer compression fiber to the neutral
modulus of elasticity determined in 11.7.4. Calculated deflec-
axis, (in.), and
tion shall not exceed building code or project specific deflec-
C = equivalent moment factor determined as follows:
b
tion limits.
11.6.3 Laterally loaded piles (for example, fender piles)
C 5 (8)
b
M M M
1 2 3
shall meet all project specific stiffness and energy absorption
3 14 13 12
S D S D S D
M M M
MAX MAX MAX
requirements.
where:
11.7 Flexural Properties (Lateral Load-bearing Piles):
M = moment at the quarter point (in.-lb),
11.7.1 Test procedure shall be in accordance with Test 1
M = moment at the half point (in.-lb),
Methods D6109 with the following modifications: 2
M = moment at the three quarter point (in.-lb), and
11.7.1.1 The minimum support span to depth ratio of each
M = maximum moment (in.-lb).
MAX
specimen shall be no less than 10:1.
(1) As an alternative, it is permissible to use C = 1.0 as a
b
11.7.1.2 The distance between the loading noses on the
conservative value.
four-point test, shall be either one third of the specimen length
or 4 ft, whichever is less.
11.7.1.3 Specimens Tested—A minimum of 28 specimens
E' = apparent modulus of elasticity as defined in 11.7.4 (psi),
shall be tested at 23 6 2°C (73.4 6 4°F). Specimens selected
I = moment of inertia about the weak axis (in. ),
y
for testing shall be representative of typical production and
I = moment of inertia about the strong axis (in. ), and
x
shall be selected to include sources of potential variability.
G' = apparent shear modulus (psi), calculated as follows:
11.7.2 A minimum of ten specimens shall be cycled five
G' 5 G/α (9)
times to 30 % of the flexural failure load and their load
where:
deflection output shall be reported. If there is more than a 10 %
loss in flexural strength or stiffness modulus, the piling product
G = shear modulus determined from tests performed in
shall not be used in load cycling applications such as fender
accordance with 11.8.1 (psi),
piling.
α = creep adjustment factor determined in accordance with
11.7.3 Allowable Flexural Stress—The allowable flexural
Annex A1,
J = torsional constant, polar moment of inertia (in. ),
stress, F ', of a product is given as follows:
b
F = base flexural stress defined above, (psi), and
b
F ' 5 F /FS ·C ·C (5)
~ !
b b TF L
D7258 − 23
L = effective unbraced length, (in.). β = stress-time factor to convert the test value, F , to a ten
u v
year normal duration value. This value shall be deter-
11.7.4 Apparent Modulus of Elasticity and Adjustment for
mined in accordance with Annex A1.
Creep—The apparent modulus of elasticity, E', shall be deter-
11.9 Bearing:
mined as follows:
11.9.1 Tests shall be performed in accordance with Test
E' 5 E/α (10)
Method D6108 with the following modifications:
where:
11.9.1.1 Specimens Tested—A minimum of 28 specimens
shall be tested at 23 6 2°C (73.4 6 4°F). Specimens selected
E = modulus as determined from Test Method D6109, ex-
for testing shall be representative of typical production and
cept that it represents the chord modulus values between
shall be selected to include sources of potential variability.
0.1 F and 0.4 F , (psi), and
bt bt
α = creep adjustment factor determined in accordance with 11.9.1.2 Bearing Perpendicular to the Direction of Extru-
Annex A3. sion:
NOTE 5—Values for α shall be provided by manufacturers for their (1) Test Method D6108 subsection 6.2: The standard test
specific products based on methodology presented in Annex A1.
specimen shall take the form of the actual manufactured
product cross-section with a length equal to half its height.
11.8 Shear Strength:
(2) Test Method D6108 subsection 10.2: Place the test
11.8.1 Test Procedure—Test Method D2344/D2344M incor-
specimen between the surfaces of the compression platens,
porating the following criteria and modifications:
taking care to align the center line of the surface perpendicular
11.8.1.1 Specimen Size for Testing—Specimens for test shall
to the extrusion with the center line of the platens to ensure that
not be machined to reduce the cross-sectional thickness—only
the ends of the specimen are parallel with the surface of the
full-size cross sections shall be used. Also, in accordance with
platens. The proper positioning of a member with dimensions
subsection 5.3 of Test Method D2344/D2344M, use span
b×d is shown in Fig. 2. Adjust the crosshead of the testing
length-to-specimen thickness ratio of 4 for the specimen size.
machine until it just contacts the top of the compression platen.
11.8.1.2 Specimens Tested—A minimum of 28 specimens
11.9.1.3 Bearing Parallel to the Direction of Extrusion:
shall be tested. Specimens selected for testing shall be repre-
(1) Test Method D6108, subsection 6.2: The standard test
sentative of typical production and shall be selected to include
specimen shall take the form of the actual manufactured
sources of potential variability.
product cross-section with a height equal to twice its length.
11.8.1.3 An extension indicator shall be affixed to the
(2) Test Method D6108, subsection 10.2: Place the test
specimen to record the displacement (strain) of the specimen
specimen between the surfaces of the compression platens,
below the upper loading nose as a function of applied stress.
taking care to align the center line of the surface parallel to the
The recorded stress-strain data shall also be reported.
extrusion with the center line of the platens to ensure that the
sbs
11.8.1.4 Use the short beam strength, F , as calculated in
ends of the specimen are parallel with the surface of the
Eq. 1 of Test Method D2344/D2344M as the shear strength
platens. The proper positioning of a member with dimensions
value F in Eq 11.
v
b×d is shown in Fig. 3. Adjust the crosshead of the testing
11.8.2 Allowable Shear Stress—The allowable shear stress
machine until it just contacts the top of the compression platen.
of a product is given as follows:
11.9.2 Bearing Perpendicular to Extrusion:
F ' 5 F /FS ·C (11)
~ ! 11.9.2.1 Allowable Bearing Stress—The allowable bearing
v v TF
stress, F ', of a product loaded in compression perpendicular
C'
where:
to the extrusion direction is given as follows:
F = the base shear stress value at 23°C (73.4°F) for
v
normal duration loading (ten-year duration), (psi) as
defined below,
FS = factor of safety = 2.0, and
C = temperature factor for flexure, determined in accor-
TF
dance with Annex A3.
11.8.2.1 F , the base shear stress value for the product is
v
determined as follows:
F 5 F ·β # F (12)
v vt cr
where:
F = the nonparametric 5 % lower tolerance limit at 75 %
vt
confidence of the shear stress at 3 % fiber strain (or
failure if 3 % strain cannot be reached) determined
from shear tests conducted in accordance with 11.8.1
(psi). Statistical calculations shall be in accordance
with Practice D2915.
F = ultimate creep rupture stress for shear calculated in
cr
accordance with 11.5, (psi), and
FIG. 2 Bearing Perpendicular to the Direction of Extrusion
D7258 − 23
F 5 F ·β # F (16)
C?? C? t cr
?
where:
F = the nonparametric 5 % lower tolerance limit at 75 %
C|| t
confidence of the bearing stress parallel to the
extrusion direction at 3 % fiber strain (or failure if
3 % strain cannot be reached) determined from
bearing tests conducted in accordance with 11.9.1
(psi). Statistical calculations shall be in accordance
with Practice D2915.
F = ultimate creep rupture stress for compression parallel
cr
to the direction of extrusion calculated in accordance
with 11.5, (psi), and
β = stress-time factor to convert the test value, F , to a
C|| t
ten year normal duration value. This value shall be
determined in accordance with Annex A1.
FIG. 3 Bearing Parallel to the Direction of Extrusion
11.10 Design Flexural Stiffness:
11.10.1 The Design Flexural Stiffness, (EI) of the pile is
D
the product of the Modulus of Elasticity, E of the pile and the
F ' 5 ~F /FS!·C (13)
C' C' TC
moment of inertia of the gross section, I. The Modulus of
Elasticity, E, is the average value of the Chord Modulus at 1 %
where:
strain determined in accordance with Test Methods D6109. Use
F = the base bearing stress value at 23°C (73.4°F), (psi)
C'
the value one standard deviation below the mean.
defined below,
FS = factor of safety = 2.0, and
11.11 Energy Absorption:
C = temperature factor for compression, determined in
TC
11.11.1 Specimens Tested—A minimum of 28 specimens
accordance with Annex A3,
shall be tested in accordance with Test Methods D6109 at 23 6
(1) F , the base bearing stress value for the product is
C'
2°C (73.4 6 4°F). The nonparametric 5 % lower tolerance
determined as follows:
limit with 75 % confidence as explained in Practice D2915
shall be used in calculations involving the measured force
F 5 F ·β # F (14)
C' C' t cr
versus deflection at 0.25 % strain. Specimens selected for
where:
testing shall be representative of typical production and shall
F = the nonparametric 5 % lower tolerance limit at 75 %
be selected to include sources of potential variability.
C' t
confidence of the bearing stress perpendicular to the
11.11.2 Test procedures shall conform to Test Methods
extrusion direction at 3 % fiber strain (or failure if
D6109 with the following modifications:
3 % strain cannot be reached) determined from
11.11.2.1 The minimum support span to depth ratio of the
bearing tests conducted in accordance with 11.9.1
specimen shall be no less than 10:1.
(psi). Statistical calculations shall be in accordance
11.11.2.2 The distance between the loading noses on the
with Practice D2915.
four-point test, shall be either one third of the specimen length
F = the ultimate creep rupture stress for bearing perpen-
cr
or 4 ft, whichever is less.
dicular to the direction of extrusion calculated in
11.11.2.3 The rate of crosshead motion shall be as follows:
accordance with 11.5, (psi), and
β = stress-time factor to convert the test value, F , to R 5 λVL ~in./s! (17)
C' t t
a ten year normal duration value. This value shall be
where:
determined in accordance with Annex A1.
V = design vessel velocity (in./s),
11.9.3 Bearing Parallel to Extrusion:
L = length of the test specimen (in.), and
t
11.9.3.1 Allowable Bearing Stress—The allowable bearing
λ = adjustment coefficient as defined in Fig. 4.
stress, F ', of a product loaded in compression parallel to the
C|| (1) d
extrusion direction is given as follows:
(2) For some design vessel velocities, the required rate of
crosshead motion exceeds realistic testing speeds. In this case,
F ' 5 F /FS ·C (15)
~ !
C?? C?? T
testing at the maximum realistic crosshead speed shall be
where:
permitted. A scale factor, as determined in 11.11.3.1, shall be
F = the base bearing stress value at 23°C (73.4°F), (psi)
applied to the allowable energy absorption determined in
C||
defined below,
11.11.3.
FS = factor of safety = 2.0, and
11.11.2.4 An average Load-Deflection plot of the specimens
C = temperature factor for compression, determined in
TC
tested shall be reported. An equation for the load-deflection
accordance with Annex A3.
curve shall be reported in the following form:
(1) F , the base bearing stress value for the product is
C||
3 2
determined as follows: P Δ 5 AΔ 1BΔ 1CΔ (18)
~ !
t t t t
D7258 − 23
Cantilever Pile Restraint at Top of Pile
All values of a a # 0.414L a > 0.414L
P P
λ
2 2 2
1.11 0.278·sa 2 3L d ·sa12L d 0.556·sa12L d
P P P
2 2 2 3
sL 2 ads2L 1ad sa1L d ·sL 2 a d·L
P p P P P a
L ·
Œ
P
a12L
P
ψ
2 2 2 3
108·sL 2 ad ·s2L 1ad 216·a·sL 2 a d
P P P 108·a·b a
·
2 2 2 Œ
23 23· 3 L 2 a
s d 23 a12L
P
P
γ
3 2 2 3
sL 2 ad·s2L 1ad 2L sL 2a d
P P P P L a
P
·
2 2 2 2 Œ
6 3 L 2 a · a 1 2 L · 3 L 2a d
s d s d s 3·a12L a12L
P p P
P P
a = distance to point of vessel impact from top of pile
L = length of pile above the mudline
P
FIG. 4 Energy Absorption Coefficients
where: 11.11.3.1 Energy Absorption Scale Factor—For piles tested
at crosshead rates other than the rate determined in 11.11.2.3,
P = force applied to the test specimen (lb), and
Δ = deflection of the test specimen (in.). the allowable energy absorption shall be scaled by the follow-
t
ing factor:
11.11.2.5 The load-deflection curve for the actual pile shall
be calculated and reported in the form: Scale Factor 5 C /C (23)
D,t D,t
b a
3 2
P~Δ ! 5 AΔ 1BΔ 1CΔ (19)
p p p p
where:
where: C = load duration factor for time t , as determined in
D,ta a
Annex A2,
A, B, and C = as calculated in 11.11.2.4, and
C = load duration factor for time t , as determined in
Δ = deflection of the pile calculated as:
D,tb b
p
Annex A2,
Δ 5 ψΔ /L ~in.! (20)
p t t
t = ε /R ,
a c dv
t = ε /R ,
where:
b f test
ε = strain at failure during test as determined in 11.11.3,
f
ψ = adjustment coefficient as defined in Fig. 4.
ε = (ε /2)·(1+ n ),
c f c
11.11.3 Allowable Energy Absorption—Allowable pile en-
n = creep coefficient as determined in Annex A1,
c
ergy absorption shall be taken as follows:
R = crosshead rate based on design vessel velocity re-
dv
Δ
quired by 11.11.2.3, and
f
U 5 P Δ dΔ (21)
* ~ !
p
0 R = actual crosshead rate used for test.
test
where:
11.12 Compressive Strength:
Δ = deflection at defined failure strain calculated as:
f
11.12.1 Test procedures shall conform to Test Method
Δ 5 2γε /d in. (22) D6108 with the following modifications:
~ !
f f
11.12.1.1 Specimens Tested—A minimum of 28 specimens
where:
shall be tested at 23 6 2°C (73.4 6 4°F). Specimens selected
γ = adjustment coefficient as defined in Fig. 4,
for testing shall be representative of typical production and
d = cross sectional depth in the direction of impact (in.), and
shall be selected to include sources of potential variability.
ε = defined failure strain, generally taken as 0.01, where:
f
11.12.2 Design of Compression Members—Laterally unsup-
ε # ε
f r
ported portions of axially loaded piles shall meet the following
where:
slenderness ratio requirement:
ε = strain at which the test specimen ruptured.
r
S 5 K L /r,28 (24)
r e u
D7258 − 23
where:
F' = allowable compressive stress under axial com-
c
S = slenderness ratio, pression only (psi), in accordance with 11.12.3,
r
K = buckling length coefficient (greater than or equal to f , f = flexural stress at service load due to primary
e bx by
1.0) that depends on the end constraint for the column, bending moment about the respective axis
L = unbraced length of the member, and (psi),
u
r = radius of gyration.
F' , F' = allowable flexural stress about the respective
bx by
axis (psi), in accordance with 11.7.3,
NOTE 6—The above slenderness ratio shall be checked for both
F' , F' = critical elastic buckling stress about the respec-
principle bending axes of the member.
ex ey
tive axis (psi), calculated as follows:
11.12.3 The allowable compressive stress of a product is
π E' I C
given as follows: TF
F' , F' 5 (29)
ex ey
2~KL ! A
u
F ' 5 ~F /FS!·C ·C (25)
c c TC P
where:
where:
E' = apparent modulus of elasticity as defined in 11.7.4
F = base compressive stress value at 23°C (73.4°F) for
c
(psi),
normal duration loading (ten-year duration), (psi) as
I = moment of inertia about the axis in which buckling is
defined below: 4
induced (in. ),
β = stress-time factor,
F 5 β·F # F (26)
c ct cr
C = temperature factor, determined in accordance with
T
where:
Annex A3,
F = nonparametric 5 % lower tolerance limit at 75 %
K = effective length factor determined by the condition of
ct
confidence of the compressive stress at 3 % fiber
the end restraint,
strain (or failure if 3 % strain cannot be reached) L = unbraced member length (in.), and
u
determined from compression tests conducted in ac- A = cross sectional area (in. ).
cordance with 11.12.1 (psi). Statistical calculations
11.14 Dimensional Stability—Thermal Expansion:
shall be in accordance with Practice D2915,
11.14.1 Test procedures shall conform to Test Method
F = ultimate creep rupture stress for compression calcu-
cr
D6341 with the following modifications:
lated in accordance with 11.5, (psi),
β = stress-time factor to convert the test value, F , to a ten
ct 11.14.1.1 Specimens Tested—A minimum of 15 specimens
year normal duration value. This value shall be
shall be tested. Specimens selected for testing shall be repre-
determined in accordance with Annex A1,
sentative of typical production and shall be selected to include
FS = factor of safety = 2.0,
sources of potential variability.
C = temperature factor for compression determined in
TC
11.14.1.2 Criteria—Report the measured thermal expansion
accordance with Annex A3,
coefficient in either the longitudinal or the transverse directions
C = column stability factor defined below:
P
to two significant figures. Thermal expansion shall be consid-
C = 1.0 for a column with lateral support throughout its
P
ered for the design of expansion slots, where polymeric piles
length. For all other columns:
are used with dissimilar materials or any other case where
π E' I
movement due to thermal effects will cause structural or
C 5 # 1.0 (27)
P 2
2~KL! A F
C
serviceability concerns.
where:
11.15 Hygrothermal Cycling:
E' = apparent modulus of elasticity as defined in 11.7.4,
11.15.1 Test Procedure—Specimens shall also be prepared
(psi),
as described in Test Method D6108. Each specimen shall be
I = moment of inertia about the weak axis,
weighed. Specimens will then be totally submerged in substi-
K = effective length factor determined by the condition of
tute ocean water created in accordance with Practice D1141
the end restraint,
(using weights to hold down, if necessary) for a period of 24
L = unbraced member length, and
hours. Each specimen shall then be dried with a dry cloth on
F = base compressive stress defined above.
C
the outside surfaces. Each specimen shall then be weighed
11.13 Combined Stresses:
again within 20 minutes of removal from the water. Specimens,
11.13.1 Combined Stresses—Bending and Compression—
which exceed a 1 % weight gain as compared to the unsoaked
Plastic members subject to both axial compression and flexure
specimen shall be resoaked until such time as the weight
shall be proportioned in accordance with the following inter-
changes less than 1 % per 24 hour period. Such specimens will
action equation:
then be considered to have reached moisture absorption equi-
librium. Specimens will then be frozen to –20°F (–29°C) for 24
f f f
c bx by
1 1 # 1.0 (28)
F' F' 1 2 f /F' F' 1 2 f /F' hours, then returned to room temperature. This process com-
~ ! ~ !
c bx a ex by a ey
prises one hygrothermal cycle. This process shall be repeated
where:
two more times, for a total of three cycles of water submersion,
f = P/A = actual compressive stress (psi),
c
moisture absorption equilibrium, and freezing. After the
D7258 − 23
completion of these steps, the specimens shall be returned to 13.3 Fender Piles—If at all possible, avoid placing a splice
room temperature and tested as described in Test Method in the region of possible contact with vessels. If splices cannot
D6108. be avoided in the possible contact area, special considerations
11.15.2 Specimen Tested—A minimum of 15 specimens shall be taken to ensure acceptable performance and durability
shall be prepared as in accordance with Test Method D6108 of the pile under these loading conditions.
and tested. Specimens selected for testing shall be representa-
14. Specimen Conditioning
tive of typical production and shall be selected to include
sources of potential variability. 14.1 Conditioning of Specimens for Tests—Unless specifi-
11.15.3 Criteria—Any obvious physical changes that occur cally stated otherwise, all specimens shall be conditioned and
as a result of the hygrothermal cycling shall be noted. The tested in accordance with the appropriate test method.
compressive modulus and the greater of the stress level of the
15. Workmanship, Finish, and Appearance
pile is product of the mean value minus one standard deviation
at 3 % strain when tested without hygrothermal cycling. 15.1 The polymeric pilings furnished in accordance with
this specification shall be an acceptable match to approved
11.16 Flame Spread Index:
samples in pattern, color, and surface appearance. The products
11.16.1 The flame spread index of pile products shall be
shall be free of defects that adversely affect performance or
determined by testing in accordance with Test Method E84.
appearance. Such defects include, but are not limited to,
11.16.2 A minimum of five test specimens shall be tested.
blemishes, spots, indentations, cracks, blisters, and breaks.
11.16.3 The test specimens shall either be self-supporting
by their own structural characteristics or held in place by added
16. Certification
supports along the test specimen surface. The test specimen
16.1 When requested, a manufacturer’s certification and any
shall remain in place throughout the test duration. Test results
other documents required to substantiate certification shall be
are invalid if one of the following occurs during the test: (a) the
furnished stating that the product was manufactured to meet
test specimen sags from its position in the ceiling to such an
this specification.
extent that it interferes with the effect of the gas flame on the
test specimen or (b) portions of the test specimen melt or drop
17. Quality Assurance
to the furnace floor to the extent that progression of the flame
17.1 This section presents a Quality Assurance program for
front on the test specimen is inhibited.
the manufacturer to put into place to verify compliance with
11.16.4 Appendix X1 of Test Method E84 provides guid-
specific portions of this specification. The program shall
ance on mounting methods.
include the following at a minimum:
11.16.5 Products shall have a flame spread index no greater
17.1.1 Product Specification, including incoming product
than 200 when tested in accordance with Test Method E84.
inspection and acceptance requirements.
NOTE 7—For combustible construction, codes often require fire perfor-
17.1.2 Sampling and inspection frequencies shall be devised
mance at least equivalent to that of wood. A maximum flame spread index
to encompass all variables that affect the quality of the finished
of 200 when tested in accordance with Test Method E84 is considered to
product including lot-to-lot variations from different produc-
be equivalent to that of wood. For outdoor applications, there is no
tion runs. Increased frequencies shall be used in connection
requirement specified for smoke developed index.
NOTE 8—Fire retardants are available to increase the resistance to
with new or revised facilities. A random sampling scheme shall
ignitability and flame spread of piles and shall be incorporated as needed.
generally be used for specimen selection.
12. Installation
NOTE 9—Increased sampling and test frequencies is a useful procedure
when investigating apparent data trends or adjustments in process. It is
12.1 Piles shall be capable of being driven by air/steam,
desirable at times to deviate from a random sampling scheme while
diesel or hydraulic hammers. Axial load bearing piles must be
investigating effects of specific variables.
capable of withstanding a striking energy from a hammer rated
17.1.3 Procedures to be followed upon failure to meet
at a minimum of 10,000 ft-lb (13.6 KJ) per blow without
specifications or upon out of control conditions shall be
damage to the pile anywhere along its length, with the
specified. Included shall be reexamination criteria for suspect
exception of a sacrificial 2 ft at driving end.
product and product rejection criteria.
13. Splicing of Piles 17.1.4 Finished product marking, handling, protection, and
shipping requirements as they relate to the performance of the
13.1 Strength—Splicing mechanisms must provide strength
finished product shall be defined.
equal to or greater than the ultimate strength of the pile proper,
in bending, compression, tension and torsion. Splices shall be 17.2 Inspection Personnel—All manufacturing personnel
tested in accordance with Test Methods D6108 and D6109 with responsible for quality control shall have knowledge of the
the splice located at the mid-span. Failure shall not occur at the inspection and test procedures used to control the process of
splice. the operation and calibration of the recording and test equip-
ment used and of maintenance and interpretation of quality
13.2 Stiffness—The stiffness of any splice, defined as the
control records.
product E times I, must provide a minimum of 100 % of pile
stiffness. For this purpose, E shall represent the Modulus of 17.3 Record Keeping—All pertinent records shall be main-
Elasticity as defined by Test Methods D6109 and I shall tained on a current basis and be available for review. Records
represent the moment of inertia of the cross section. shall include:
D7258 − 23
17.3.1 Inspection reports and records of test equipment specification, substituting or modifying a test method or by
calibration, including identification of personnel conducting changing the
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D7258 − 17 D7258 − 23
Standard Specification for
Polymeric Piles
This standard is issued under the fixed designation D7258; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This specification addresses the use of round and rectangular cross-section polymeric piles in axial and lateral load-bearing
applications, including but not limited to marine, waterfront, and corrosive environments.
1.2 This specification is only applicable to individual polymeric pile products. Sheet pile and other mechanically connected
polymeric pile products using inter-locking systems, are not part of this specification.
1.3 The piling products considered herein are characterized by the use of polymers, whereby (1) the pile strength or stiffness
requires the inclusion of the polymer, or (2) a minimum of fifty percent (50 %) of the weight or volume is derived from the
polymer. The type classifications of polymeric piles described in Section 4 show how they can be reinforced by composite design
for increased stiffness or strength.
1.4 This specification covers polymeric piles fabricated from materials that are virgin, recycled, or both, as long as the finished
product meets all of the criteria specified herein. Diverse types and combinations of inorganic filler systems are permitted in the
manufacturing of polymeric piling products. Inorganic fillers include such materials as talc, mica, silica, wollastonite, calcium
carbonate, etc. Pilings are often placed in service where they will be subjected to continuous damp or wet exposure conditions.
Due to concerns of water sensitivity and possible affects on mechanical properties in such service conditions, organic fillers,
including lignocellulosic materials such as those made or derived from wood, wood flour, flax shive, rice hulls, wheat straw, and
combinations thereof, are not permitted in the manufacturing of polymeric piling products.
1.5 The values are stated in inch-pound units as these are currently the most common units used by the construction industry.
1.6 Polymeric piles under this specification are designed using design stresses determined in accordance with Test Methods
D6108, D6109, and D6112 and procedures contained within this specification unless otherwise specified.
1.7 Although in some instances it will be an important component of the pile design, frictional properties are currently beyond
the scope of this document.
1.8 Criteria for design are included as part of this specification for polymeric piles. Certain Types and sizes of polymeric piles will
be better suited for some applications than others. Polymeric piles designed and manufactured under the different Type
classifications as defined within this specification will, as a whole, exhibit a wide-range of mechanical properties. For example,
a 10-in. diameter Type II, chopped glass fiber reinforced high-density polyethylene (HDPE) pile will likely have an apparent
stiffness much different than a 10-in. diameter Type V, glass fiber reinforced composite tube filled with concrete. Similarly, the
This specification is under the jurisdiction of ASTM Committee D20 on Plastics and is the direct responsibility of Subcommittee D20.20 on Plastic Lumber.
Current edition approved March 1, 2017Feb. 1, 2023. Published March 2017February 2023. Originally approved in 2009. Last previous edition approved in 20142017
as D7258 – 14. DOI: 10.1520/D7258-17.17. DOI: 10.1520/D7258-23.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7258 − 23
ultimate moment capacity of these two example piles will also likely be significantly different from each other. Use of a licensed
Professional Engineer is, therefore, highly recommended for designing and selecting polymeric piles in accordance with this
specification.
1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and healthsafety, health, and environmental practices and determine
the applicability of regulatory limitations prior to use.
NOTE 1—There is no known ISO equivalent to this specification.
1.10 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D883 Terminology Relating to Plastics
D1141 Practice for Preparation of Substitute Ocean Water
D2344/D2344M Test Method for Short-Beam Strength of Polymer Matrix Composite Materials and Their Laminates
D2915 Practice for Sampling and Data-Analysis for Structural Wood and Wood-Based Products
D5033 Guide for Development of ASTM Standards Relating to Recycling and Use of Recycled Plastics (Withdrawn 2007)
D6108 Test Method for Compressive Properties of Plastic Lumber and Shapes
D6109 Test Methods for Flexural Properties of Unreinforced and Reinforced Plastic Lumber and Related Products
D6112 Test Methods for Compressive and Flexural Creep and Creep-Rupture of Plastic Lumber and Shapes
D6341 Test Method for Determination of the Linear Coefficient of Thermal Expansion of Plastic Lumber and Plastic Lumber
Shapes Between –30 and 140°F (–34.4 and 60°C)
D6662 Specification for Polyolefin-Based Plastic Lumber Decking Boards
E84 Test Method for Surface Burning Characteristics of Building Materials
E176 Terminology of Fire Standards
2.2 Other Documents:
ASCE 7 Minimum Design Loads for Buildings and Other Structures
AASHTO GSDPB-1 Standard Specification for Design of Pedestrian Bridges
AASHTO HB-13 Standard Specification for Highway Bridges
Department of Defense Unified Facility Criteria UFC 4-152-01 Design: Piers and Wharves, Naval Facilities Engineering
Command, Washington DC
3. Terminology
3.1 Definitions of Terms:
3.1.1 For definitions of terms used in this specification associated with plastics issues refer to the terminology contained in
Terminology D883. For definitions of terms used in this specification and associated with fire issues refer to the terminology
contained in Terminology E176. Additional definitions of terms applying to this specification appear in Guide D5033.
3.1.2 plastic lumber, n—a manufactured product made primarily from plastic materials (filled or unfilled), typically used as a
building material for purposes similar to those of traditional lumber, which is usually rectangular in cross-section. D883
3.1.2.1 Discussion—
Plastic lumber is typically supplied in sizes similar to those of traditional lumber board, timber and dimension lumber; however
the tolerances for plastic lumber and for traditional lumber are not necessarily the same. D883
3.2 Definitions:Definitions of Terms Specific to This Standard:
3.2.1 axial load-bearing pile, n—a vertical or battered member driven into the ground to help support a load of any structure
bearing upon it. Axial load-bearing piles are commonly divided into two kinds; point-bearing (end-bearing) and friction. A
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
The last approved version of this historical standard is referenced on www.astm.org.
Available from American Society of Civil Engineers (ASCE), 1801 Alexander Bell Dr., Reston, VA 20191, http://www.asce.org.
Available from American Association of State Highway and Transportation Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
http://www.transportation.org.
D7258 − 23
point-bearing pile derives practically all its support from the rock or soils near the point and much less from contact with soil along
the pile shaft. A friction pile derives its support principally from the soil along the pile shaft through the development of shearing
resistance between the soil and the pile.
3.2.2 lateral load-bearing pile, n—a vertical or battered member driven into the ground to resist lateral loads imposed upon it or
a structure. A common application for a lateral load-bearing pile is to absorb lateral forces at points of impact and dissipate them
horizontally into a structure and/or soil stratum. A fender pile is an example of a lateral load-bearing pile.
3.2.3 combined axial and lateral load-bearing pile, n—a vertical or battered member driven into the ground to resist both axial
and lateral loads or applied external forces imposed upon it. Combined axial and lateral load-bearing piles are commonly divided
into two kinds; point-bearing (end-bearing) and friction. A point-bearing pile derives practically all its support from the rock or
soils near the point and much less from contact with soil along the pile shaft. A friction pile derives its support principally from
the soil along the pile shaft through the development of shearing resistance between the soil and the pile.
3.2 Additional definitions of terms applying to this specification appear in Terminology D883 and Guide D5033.
4. Classification
4.1 Polymeric Piles contained in this specification are classified as following six (6) types:
4.1.1 Type I—Polymeric only.
4.1.2 Type II—Polymeric with reinforcement in the form of chopped, milled or continuous fiber or mineral.
4.1.3 Type III—Polymeric with reinforcement in the form of metallic bars, cages, or shapes.
4.1.4 Type IV—Polymeric with reinforcement in the form of non-metallic bars or cages.
4.1.5 Type V—Polymeric composite tube with a concrete core.
4.1.6 Type VI—Any other polymeric piling meeting the requirements in 1.3 and not otherwise described by Types I through V
above.
5. Ordering Information
5.1 The purchaser shall state whether this specification is to be used, select the preferred options permitted herein, and include the
following information in the invitation to bid and purchase order:
5.1.1 Title, number and date of this specification,
5.1.2 Type and composition,
5.1.3 Percent recycled content (if requested),
5.1.4 Flame spread index, if applicable,
5.1.5 Color,
5.1.6 Quantity in linear feet (meters), and minimum length without splices,
5.1.7 Cross-sectional dimensions,
5.1.8 Performance requirements including flexural strength, axial strength, and stiffness,
5.1.9 Required accessories including pile tips, splices and driving caps,
5.1.10 Special handling, packing, or shipping requirements,
D7258 − 23
5.1.11 Marking, if other than specified, and
5.1.12 Shop drawings and submittals.
6. Tolerances
6.1 Sizes:
6.1.1 Circular Piles:
6.1.1.1 Maximum deviation from a circular cross section shall be:
b 5 0.98a (1)
where:
2a = major oval diameter, and
2b = minor oval diameter.
(1) For example, for 13 in. (330 mm) major diameter pile, maximum allowable difference between major and minor diameter
would be 0.26 in. (7 mm).
6.1.1.2 Diameter—Tolerance against specified diameter = 63 %.
6.1.2 Rectangular Piles:
6.1.2.1 Squareness of Piles—Measurements of the two opposing diagonals shall not differ by more than 3 %, calculated with the
smaller diagonal denominator.
6.1.2.2 Dimensions shall not vary from specified dimension by more than 3 %.
6.1.3 Cross-Section—All piles, regardless of cross sectional shape shall remain consistent in cross-sectional area along the length
of the pile, except that a tolerance of 66 % is permitted against the nominal or specified area at any location along the length of
pile.
6.1.4 Each pile shall be measured at a minimum of three locations at quarter points along its length, prior to shipment, to confirm
compliance with this section.
6.1.5 Pile head tolerance from the plane perpendicular to the longitudinal axis of the pile shall be ⁄4 in. (6 mm) in 12 in. (305 mm)
but not more than ⁄2 in. over the whole pile length (12 mm).
7. Lengths
7.1 All piles shall be furnished in lengths specified, except that tolerances shall be plus 1 ft (0.3 m), minus 0 in. (0 mm) corrected
to 73°F, and
7.2 Piles 41 ft or longer—plus 2 ft (0.6 m), minus 0 in (0 mm) corrected to 73°F.
8. Straightness
8.1 A straight line from the center of the head to the center of the tip shall lie entirely within the body of the pile when the pile
is vertically suspended from the head.
8.2 Lateral load-bearing piles shall be free of short crooks that deviate more than 2 ⁄2 in. (64 mm) from straightness in any 20 ft
(1.5 m) length. See Fig. 1.
8.3 Axial load-bearing piles shall have no more than 1 in. (24 mm) bow or bend in 20 ft (6.5 m) of length.
D7258 − 23
FIG. 1 Measurement of Short Crook N.T.S.
8.4 Straightness as defined in 8.2 and 8.3 shall be interpreted as the as-built straightness.
9. Placement of Reinforcement for Pile Types III and IV only
9.1 Longitudinal reinforcement shall remain within 5 % of the specified radial location as measured from centroid of the
cross-section of the pile.
9.2 Longitudinal reinforcement shall not twist more than 5° over any 20 ft (6.1 m) section of the pile.
10. Surface Condition
10.1 The pile surface will typically exhibit some roughness or corrugations due to manufacturing processes. However, the piles
D7258 − 23
shall not have depressions or projections greater than ⁄2 in. (13 mm) and the total surface area of any such depressions or
2 2
projections shall not be greater than 9 in. (58 cm ).
10.2 The surface of the pile shall contain no cracks or splits, in any orientation.
11. Performance Requirements
11.1 The cross-sectional dimensions of piles will be determined on the basis of the ability to perform satisfactorily under the
physical loading and environmental conditions imposed as well as the energy absorption properties desired. Testing methods and
procedures for analysis of results to define allowable values for the design of plastic piles are given below.
11.2 Load Combinations—Polymeric piles subject to multiple load types shall be checked for all applicable load combinations.
Load factors and load reductions shall be determined in accordance with the applicable code or ASCE 7. Where allowed by the
applicable code or ASCE 7, allowable stress increases are permitted. Each load type in combination shall be divided by the load
duration factor corresponding to the load type’s duration. See A2.1 for the procedure to determine the load duration factor. A
sample calculation of the load duration factor is provided in Appendix X1.
NOTE 2—Applicable codes vary depending upon location and usage. Relevant codes may include, but are not limited to, American Association of State
Highway and Transportation Officials (AASHTO) HB-13, Standard Specification for Highway Bridges, AASHTO GSDPB-1, Standard Specification for
Design of Pedestrian Bridges, or Department of Defense Unified Facility Criteria (UFC) 4-152-01 Design: Piers and Wharves.
11.3 Design Strength:
11.3.1 All piles shall be designed such that for all load combinations:
f # F ' ×C (2)
a n D
where:
f = total applied stress in each combination (psi),
a
F ' = allowable stress as calculated in 11.7.3, 11.8.2, 11.9.2, 11.9.3, or 11.12.2 (psi), and
n
C = Load Duration Factor for the material and considered load duration. Derivation of C is explained in Annex A2.
D D
NOTE 3—Results from testing of plastic lumber decking boards after eleven years of outdoor exposure have shown that the boards had discolored and
faded, but that both strength and stiffness were basically unchanged. Similar results are expected with polymeric piles made with similar materials.
Introduction of carbon black and other additives can significantly reduce ultraviolet light degradation of polymers. Further details of this testing and results
are given in Appendix X3 in Specification D6662.
11.4 Interpolation of Mechanical Properties:
11.4.1 Interpolation of mechanical properties of a polymeric pile from other pile test data is permitted if the test results verify a
logical progression of properties and the following conditions are met:
11.4.1.1 All specimens have the same and material composition.
11.4.1.2 Three or more tests are performed on specimens with varying width or diameter.
11.4.1.3 At least one test is performed on specimens with a width or diameter greater than that of the product whose properties
are being interpolated.
11.4.1.4 At least one test is performed on specimens with a width or diameter less than that of the product whose properties are
being interpolated.
11.4.1.5 For rectangular piles all specimens have the same thickness.
11.5 Creep Rupture:
D7258 − 23
11.5.1 Creep rupture tests shall be performed for the intended use (that is, flexural test for a flexural member, compression test
for a compression member) in accordance with the procedures outlined in Test Methods D6112 including the following
modifications:
11.5.1.1 The stress in the outer fiber, as indicated in subsection 12.3.1 of Test Methods D6112, in flexural creep tests shall be
modified to be calculated as follows:
M
F 5 (3)
S
where:
F = the stress in the outer fiber throughout load span, (psi),
S = section modulus (in. ), and
M = Bending Moment.
11.5.1.2 The maximum strain, as indicated in subsection 12.3.2 of Test Methods D6112, in the outer fiber at the mid-span is
calculated as follows:
ξ5 9.39·y·Δ/L (4)
where:
y = distance from the outer fiber to the centroid of the section, (in.),
Δ = maximum deflection at mid-span, (in.), and
L = support span, (in.).
11.5.2 F shall be the stress required to cause creep rupture in ten years determined from the creep rupture curve calculated in
cr
Test Methods D6112.
11.6 Serviceability:
11.6.1 The maximum ten-year strain in any member shall not exceed 0.03 (3 %).
NOTE 4—Applicable codes or project specific requirements may require deflection limits that result in a maximum strain of less than 0.03.
11.6.2 Deflection shall be calculated using the apparent modulus of elasticity determined in 11.7.4. Calculated deflection shall not
exceed building code or project specific deflection limits.
11.6.3 Laterally loaded piles (for example, fender piles) shall meet all project specific stiffness and energy absorption
requirements.
11.7 Flexural Properties (Lateral Load-bearing Piles):
11.7.1 Test procedure shall be in accordance with Test Methods D6109 with the following modifications:
11.7.1.1 The minimum support span to depth ratio of each specimen shall be no less than 10:1.
11.7.1.2 The distance between the loading noses on the four-point test, shall be either one third of the specimen length or 4 ft,
whichever is less.
11.7.1.3 Specimens Tested—A minimum of 28 specimens shall be tested at 23 6 2°C (73.4 6 4°F). Specimens selected for testing
shall be representative of typical production and shall be selected to include sources of potential variability.
11.7.2 A minimum of ten specimens shall be cycled five times to 30 % of the flexural failure load and their load deflection output
shall be reported. If there is more than a 10 % loss in flexural strength or stiffness modulus, the piling product shall not be used
in load cycling applications such as fender piling.
D7258 − 23
11.7.3 Allowable Flexural Stress—The allowable flexural stress, F ', of a product is given as follows:
b
F '5 F /FS ·C ·C (5)
~ !
b b TF L
where:
F = the base flexural stress value at 23°C (73.4°F) for normal duration loading (ten-year duration), (psi) as defined as follows:
b
F 5 F ·β# F (6)
b bt cr
where:
F = the nonparametric 5 % lower tolerance limit at 75 % confidence of the flexural stress at 3 % outer fiber strain (or failure
bt
if 3 % strain cannot be reached) determined from flexure tests conducted in accordance with 11.7.1 (psi). Statistical
calculations shall be in accordance with Practice D2915.
F = ultimate creep rupture stress for flexure calculated in accordance with 11.5, (psi),
cr
β = stress-time factor to convert the test value, F , to a ten year normal duration value. This value shall be determined in
bt
accordance with Annex A1,
FS = factor of safety = 2.0,
C = temperature factor for flexure determined in accordance with Annex A3, and
TF
C = beam stability factor defined as follows:
L
11.7.3.1 C = 1.0 for a beam with a thickness greater than or equal to its depth (t ≥ d), round sections, or a beam with full lateral
L
support. For all other beams:
c·C ·π E' I G' J
b y
C 5 ·Œ # 1.0 (7)
S D
L
I ·F ·L ~12I /I !
x b u y x
where:
c = distance from outer compression fiber to the neutral axis, (in.), and
C = equivalent moment factor determined as follows:
b
C 5 (8)
b
M M M
1 2 3
3 14 13 12
S D S D S D
M M M
MAX MAX MAX
where:
M = moment at the quarter point (in.-lb),
M = moment at the half point (in.-lb),
M = moment at the three quarter point (in.-lb), and
M = maximum moment (in.-lb).
MAX
(1) As an alternative, it is permissible to use C = 1.0 as a conservative value.
b
E' = apparent modulus of elasticity as defined in 11.7.4 (psi),
I = moment of inertia about the weak axis (in. ),
y
I = moment of inertia about the strong axis (in. ), and
x
G' = apparent shear modulus (psi), calculated as follows:
G'5 G/α (9)
where:
G = shear modulus determined from tests performed in accordance with 11.8.1 (psi),
α = creep adjustment factor determined in accordance with Annex A1,
J = torsional constant, polar moment of inertia (in. ),
F = base flexural stress defined above, (psi), and
b
L = effective unbraced length, (in.).
u
D7258 − 23
11.7.4 Apparent Modulus of Elasticity and Adjustment for Creep—The apparent modulus of elasticity, E', shall be determined as
follows:
E'5E/α (10)
where:
E = modulus as determined from Test Method D6109, except that it represents the chord modulus values between 0.1 F and
bt
0.4 F , (psi), and
bt
α = creep adjustment factor determined in accordance with Annex A3.
NOTE 5—Values for α shall be provided by manufacturers for their specific products based on methodology presented in Annex A1.
11.8 Shear Strength:
11.8.1 Test Procedure—Test Method D2344/D2344M incorporating the following criteria and modifications:
11.8.1.1 Specimen Size for Testing—Specimens for test shall not be machined to reduce the cross-sectional thickness—only
full-size cross sections shall be used. Also, in accordance with subsection 5.3 of Test Method D2344/D2344M, use span
length-to-specimen thickness ratio of 4 for the specimen size.
11.8.1.2 Specimens Tested—A minimum of 28 specimens shall be tested. Specimens selected for testing shall be representative of
typical production and shall be selected to include sources of potential variability.
11.8.1.3 An extension indicator shall be affixed to the specimen to record the displacement (strain) of the specimen below the
upper loading nose as a function of applied stress. The recorded stress-strain data shall also be reported.
sbs
11.8.1.4 Use the short beam strength, F , as calculated in Eq. 1 of Test Method D2344/D2344M as the shear strength value F
v
in Eq 11.
11.8.2 Allowable Shear Stress—The allowable shear stress of a product is given as follows:
F '5 ~F /FS!·C (11)
v v TF
where:
F = the base shear stress value at 23°C (73.4°F) for normal duration loading (ten-year duration), (psi) as defined below,
v
FS = factor of safety = 2.0, and
C = temperature factor for flexure, determined in accordance with Annex A3.
TF
11.8.2.1 F , the base shear stress value for the product is determined as follows:
v
F 5 F ·β# F (12)
v vt cr
where:
F = the nonparametric 5 % lower tolerance limit at 75 % confidence of the shear stress at 3 % fiber strain (or failure if 3 %
vt
strain cannot be reached) determined from shear tests conducted in accordance with 11.8.1 (psi). Statistical calculations
shall be in accordance with Practice D2915.
F = ultimate creep rupture stress for shear calculated in accordance with 11.5, (psi), and
cr
β = stress-time factor to convert the test value, F , to a ten year normal duration value. This value shall be determined in
v
accordance with Annex A1.
11.9 Bearing:
11.9.1 Tests shall be performed in accordance with Test Method D6108 with the following modifications:
11.9.1.1 Specimens Tested—A minimum of 28 specimens shall be tested at 23 6 2°C (73.4 6 4°F). Specimens selected for testing
shall be representative of typical production and shall be selected to include sources of potential variability.
D7258 − 23
11.9.1.2 Bearing Perpendicular to the Direction of Extrusion:
(1) Test Method D6108 subsection 6.2: The standard test specimen shall take the form of the actual manufactured product
cross-section with a length equal to half its height.
(2) Test Method D6108 subsection 10.2: Place the test specimen between the surfaces of the compression platens, taking care
to align the center line of the surface perpendicular to the extrusion with the center line of the platens to ensure that the ends of
the specimen are parallel with the surface of the platens. The proper positioning of a member with dimensions b×d is shown in
Fig. 2. Adjust the crosshead of the testing machine until it just contacts the top of the compression platen.
11.9.1.3 Bearing Parallel to the Direction of Extrusion:
(1) Test Method D6108, subsection 6.2: The standard test specimen shall take the form of the actual manufactured product
cross-section with a height equal to twice its length.
(2) Test Method D6108, subsection 10.2: Place the test specimen between the surfaces of the compression platens, taking care
to align the center line of the surface parallel to the extrusion with the center line of the platens to ensure that the ends of the
specimen are parallel with the surface of the platens. The proper positioning of a member with dimensions b×d is shown in Fig.
3. Adjust the crosshead of the testing machine until it just contacts the top of the compression platen.
11.9.2 Bearing Perpendicular to Extrusion:
11.9.2.1 Allowable Bearing Stress—The allowable bearing stress, F ', of a product loaded in compression perpendicular to the
C'
extrusion direction is given as follows:
F '5 F /FS ·C (13)
~ !
C' C' TC
where:
F = the base bearing stress value at 23°C (73.4°F), (psi) defined below,
C'
FS = factor of safety = 2.0, and
C = temperature factor for compression, determined in accordance with Annex A3,
TC
(1) F , the base bearing stress value for the product is determined as follows:
C'
F 5 F ·β# F (14)
C' C' t cr
where:
F = the nonparametric 5 % lower tolerance limit at 75 % confidence of the bearing stress perpendicular to the extrusion
C' t
direction at 3 % fiber strain (or failure if 3 % strain cannot be reached) determined from bearing tests conducted in
accordance with 11.9.1 (psi). Statistical calculations shall be in accordance with Practice D2915.
F = the ultimate creep rupture stress for bearing perpendicular to the direction of extrusion calculated in accordance with
cr
11.5, (psi), and
β = stress-time factor to convert the test value, F , to a ten year normal duration value. This value shall be determined
C' t
in accordance with Annex A1.
FIG. 2 Bearing Perpendicular to the Direction of Extrusion
D7258 − 23
FIG. 3 Bearing Parallel to the Direction of Extrusion
11.9.3 Bearing Parallel to Extrusion:
11.9.3.1 Allowable Bearing Stress—The allowable bearing stress, F ', of a product loaded in compression parallel to the extrusion
C||
direction is given as follows:
F '5 F /FS ·C (15)
~ !
C?? C?? T
where:
F = the base bearing stress value at 23°C (73.4°F), (psi) defined below,
C||
FS = factor of safety = 2.0, and
C = temperature factor for compression, determined in accordance with Annex A3.
TC
(1) F , the base bearing stress value for the product is determined as follows:
C||
F 5 F ·β# F (16)
C?? C? t cr
?
where:
F = the nonparametric 5 % lower tolerance limit at 75 % confidence of the bearing stress parallel to the extrusion direction
C|| t
at 3 % fiber strain (or failure if 3 % strain cannot be reached) determined from bearing tests conducted in accordance
with 11.9.1 (psi). Statistical calculations shall be in accordance with Practice D2915.
F = ultimate creep rupture stress for compression parallel to the direction of extrusion calculated in accordance with 11.5,
cr
(psi), and
β = stress-time factor to convert the test value, F , to a ten year normal duration value. This value shall be determined in
C|| t
accordance with Annex A1.
11.10 Design Flexural Stiffness:
11.10.1 The Design Flexural Stiffness, (EI) of the pile is the product of the Modulus of Elasticity, E of the pile and the moment
D
of inertia of the gross section, I. The Modulus of Elasticity, E, is the average value of the Chord Modulus at 1 % strain determined
in accordance with Test Methods D6109. Use the value one standard deviation below the mean.
11.11 Energy Absorption:
11.11.1 Specimens Tested—A minimum of 28 specimens shall be tested in accordance with Test Methods D6109 at 23 6 2°C (73.4
6 4°F). The nonparametric 5 % lower tolerance limit with 75 % confidence as explained in Practice D2915 shall be used in
calculations involving the measured force versus deflection at 0.25 % strain. Specimens selected for testing shall be representative
of typical production and shall be selected to include sources of potential variability.
11.11.2 Test procedures shall conform to Test Methods D6109 with the following modifications:
D7258 − 23
11.11.2.1 The minimum support span to depth ratio of the specimen shall be no less than 10:1.
11.11.2.2 The distance between the loading noses on the four-point test, shall be either one third of the specimen length or 4 ft,
whichever is less.
11.11.2.3 The rate of crosshead motion shall be as follows:
R 5 λVL ~in./s! (17)
t
where:
V = design vessel velocity (in./s),
L = length of the test specimen (in.), and
t
λ = adjustment coefficient as defined in Fig. 4.
(1) d
(2) For some design vessel velocities, the required rate of crosshead motion exceeds realistic testing speeds. In this case, testing
at the maximum realistic crosshead speed shall be permitted. A scale factor, as determined in 11.11.3.1, shall be applied to the
allowable energy absorption determined in 11.11.3.
11.11.2.4 An average Load-Deflection plot of the specimens tested shall be reported. An equation for the load-deflection curve
shall be reported in the following form:
3 2
P~Δ ! 5 AΔ 1BΔ 1CΔ (18)
t t t t
where:
P = force applied to the test specimen (lb), and
Δ = deflection of the test specimen (in.).
t
11.11.2.5 The load-deflection curve for the actual pile shall be calculated and reported in the form:
3 2
P~Δ ! 5 AΔ 1BΔ 1CΔ (19)
p p p p
Cantilever Pile Restraint at Top of Pile
All values of a a # 0.414L a > 0.414L
P P
λ
2 2 2
1.11 0.278· a 23L · a12L 0.556· a12L
s d s d s d
P P P
2 2 2 3
sL 2ads2L 1ad sa1L d ·sL 2a d·L
a
P p P P P
L ·Œ
P
a12L
P
ψ
2 2 2 3
108·sL 2ad ·s2L 1ad 216·a·sL 2a d
108·a·b a
P P P
2 2 2 ·Œ
23 23·s3 L 2a d
P 23 a12L
P
γ
3 2 2 3
sL 2ad·s2L 1ad 2L sL 2a d
L a
P P P P
P
2 2 2 2 ·Œ
6 3sL 2ad ·sa 1 2 L d·s3 L 2a d
P p P 3·a12L a12L
P P
a = distance to point of vessel impact from top of pile
L = length of pile above the mudline
P
FIG. 4 Energy Absorption Coefficients
D7258 − 23
where:
A, B, and C = as calculated in 11.11.2.4, and
Δ = deflection of the pile calculated as:
p
Δ 5 ψΔ /L in. (20)
~ !
p t t
where:
ψ = adjustment coefficient as defined in Fig. 4.
11.11.3 Allowable Energy Absorption—Allowable pile energy absorption shall be taken as follows:
Δ
f
U 5 P~Δ !dΔ (21)
*
p
where:
Δ = deflection at defined failure strain calculated as:
f
Δ 5 2γε /d in. (22)
~ !
f f
where:
γ = adjustment coefficient as defined in Fig. 4,
d = cross sectional depth in the direction of impact (in.), and
ε = defined failure strain, generally taken as 0.01, where:
f
ε # ε
f r
where:
ε = strain at which the test specimen ruptured.
r
11.11.3.1 Energy Absorption Scale Factor—For piles tested at crosshead rates other than the rate determined in 11.11.2.3, the
allowable energy absorption shall be scaled by the following factor:
Scale Factor 5 C /C (23)
D,t D,t
b a
where:
C = load duration factor for time t , as determined in Annex A2,
D,ta a
C = load duration factor for time t , as determined in Annex A2,
D,tb b
t = ε /R ,
a c dv
t = ε /R ,
b f test
ε = strain at failure during test as determined in 11.11.3,
f
ε = (ε /2)·(1+ n ),
c f c
n = creep coefficient as determined in Annex A1,
c
= crosshead rate based on design vessel velocity required by 11.11.2.3, and
R
dv
R = actual crosshead rate used for test.
test
11.12 Compressive Strength:
11.12.1 Test procedures shall conform to Test Method D6108 with the following modifications:
11.12.1.1 Specimens Tested—A minimum of 28 specimens shall be tested at 23 6 2°C (73.4 6 4°F). Specimens selected for testing
shall be representative of typical production and shall be selected to include sources of potential variability.
11.12.2 Design of Compression Members—Laterally unsupported portions of axially loaded piles shall meet the following
slenderness ratio requirement:
S 5 K L /r,28 (24)
r e u
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where:
S = slenderness ratio,
r
K = buckling length coefficient (greater than or equal to 1.0) that depends on the end constraint for the column,
e
L = unbraced length of the member, and
u
r = radius of gyration.
NOTE 6—The above slenderness ratio shall be checked for both principle bending axes of the member.
11.12.3 The allowable compressive stress of a product is given as follows:
F '5 F /FS ·C ·C (25)
~ !
c c TC P
where:
F = base compressive stress value at 23°C (73.4°F) for normal duration loading (ten-year duration), (psi) as defined below:
c
F 5 β·F # F (26)
c ct cr
where:
F = nonparametric 5 % lower tolerance limit at 75 % confidence of the compressive stress at 3 % fiber strain (or failure if 3 %
ct
strain cannot be reached) determined from compression tests conducted in accordance with 11.12.1 (psi). Statistical
calculations shall be in accordance with Practice D2915,
F = ultimate creep rupture stress for compression calculated in accordance with 11.5, (psi),
cr
β = stress-time factor to convert the test value, F , to a ten year normal duration value. This value shall be determined in
ct
accordance with Annex A1,
FS = factor of safety = 2.0,
C = temperature factor for compression determined in accordance with Annex A3,
TC
C = column stability factor defined below:
P
C = 1.0 for a column with lateral support throughout its length. For all other columns:
P
π E' I
C 5 # 1.0 (27)
P 2
2~KL! A F
C
where:
E' = apparent modulus of elasticity as defined in 11.7.4, (psi),
I = moment of inertia about the weak axis,
K = effective length factor determined by the condition of the end restraint,
L = unbraced member length, and
F = base compressive stress defined above.
C
11.13 Combined Stresses:
11.13.1 Combined Stresses—Bending and Compression—Plastic members subject to both axial compression and flexure shall be
proportioned in accordance with the following interaction equation:
f f f
c bx by
1 1 # 1.0 (28)
F' F' ~12 f /F' ! F' ~12 f /F' !
c bx a ex by a ey
where:
f = P/A = actual compressive stress (psi),
c
F' = allowable compressive stress under axial compression only (psi), in accordance with 11.12.3,
c
f , f = flexural stress at service load due to primary bending moment about the respective axis (psi),
bx by
F' , F' = allowable flexural stress about the respective axis (psi), in accordance with 11.7.3,
bx by
F' , F' = critical elastic buckling stress about the respective axis (psi), calculated as follows:
ex ey
π E' I C
TF
F' , F' 5 (29)
ex ey 2
2 KL A
~ !
u
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where:
E' = apparent modulus of elasticity as defined in 11.7.4 (psi),
I = moment of inertia about the axis in which buckling is induced (in. ),
β = stress-time factor,
C = temperature factor, determined in accordance with Annex A3,
T
K = effective length factor determined by the condition of the end restraint,
L = unbraced member length (in.), and
u
A = cross sectional area (in. ).
11.14 Dimensional Stability—Thermal Expansion:
11.14.1 Test procedures shall conform to Test Method D6341 with the following modifications:
11.14.1.1 Specimens Tested—A minimum of 15 specimens shall be tested. Specimens selected for testing shall be representative
of typical production and shall be selected to include sources of potential variability.
11.14.1.2 Criteria—Report the measured thermal expansion coefficient in either the longitudinal or the transverse directions to two
significant figures. Thermal expansion shall be considered for the design of expansion slots, where polymeric piles are used with
dissimilar materials or any other case where movement due to thermal effects will cause structural or serviceability concerns.
11.15 Hygrothermal Cycling:
11.15.1 Test Procedure—Specimens shall also be prepared as described in Test Method D6108. Each specimen shall be weighed.
Specimens will then be totally submerged in substitute ocean water created in accordance with Practice D1141 (using weights to
hold down, if necessary) for a period of 24 hours. Each specimen shall then be dried with a dry cloth on the outside surfaces. Each
specimen shall then be weighed again within 20 minutes of removal from the water. Specimens, which exceed a 1 % weight gain
as compared to the unsoaked specimen shall be resoaked until such time as the weight changes less than 1 % per 24 hour period.
Such specimens will then be considered to have reached moisture absorption equilibrium. Specimens will then be frozen to –20°F
(–29°C) for 24 hours, then returned to room temperature. This process comprises one hygrothermal cycle. This process shall be
repeated two more times, for a total of three cycles of water submersion, moisture absorption equilibrium, and freezing. After the
completion of these steps, the specimens shall be returned to room temperature and tested as described in Test Method D6108.
11.15.2 Specimen Tested—A minimum of 15 specimens shall be prepared as in accordance with Test Method D6108 and tested.
Specimens selected for testing shall be representative of typical production and shall be selected to include sources of potential
variability.
11.15.3 Criteria—Any obvious physical changes that occur as a result of the hygrothermal cycling shall be noted. The compressive
modulus and the greater of the stress level of the pile is product of the mean value minus one standard deviation at 3 % strain when
tested without hygrothermal cycling.
11.16 Flame Spread Index:
11.16.1 The flame spread index of pile products shall be determined by testing in accordance with Test Method E84.
11.16.2 A minimum of five test specimens shall be tested.
11.16.3 The test specimens shall either be self-supporting by their own structural characteristics or held in place by added supports
along the test specimen surface. The test specimen shall remain in place throughout the test duration. Test results are invalid if one
of the following occurs during the test: (a) the test specimen sags from its position in the ceiling to such an extent that it interferes
with the effect of the gas flame on the test specimen or (b) portions of the test specimen melt or drop to the furnace floor to the
extent that progression of the flame front on the test specimen is inhibited.
11.16.4 Appendix X1 of Test Method E84 provides guidance on mounting methods.
11.16.5 Products shall have a flame spread index no greater than 200 when tested in accordance with Test Method E84.
NOTE 7—For combustible construction, codes often require fire performance at least equivalent to that of wood. A maximum flame spread index of 200
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when tested in accordance with Test Method E84 is considered to be equivalent to that of wood. For outdoor applications, there is no requirement specified
for smoke developed index.
NOTE 8—Fire retardants are available to increase the resistance to ignitability and flame spread of piles and shall be incorporated as needed.
12. Installation
12.1 Piles shall be capable of being driven by air/steam, diesel or hydraulic hammers. Axial load bearing piles must be capable
of withstanding a striking energy from a hammer rated at a minimum of 10,000 ft-lb (13.6 KJ) per blow without damage to the
pile anywhere along its length, with the exception of a sacrificial 2 ft at driving end.
13. Splicing of Piles
13.1 Strength—Splicing mechanisms must provide strength equal to or greater than the ultimate strength of the pile proper, in
bending, compression, tension and torsion. Splices shall be tested in accordance with Test Methods D6108 and D6109 with the
splice located at the mid-span. Failure shall not occur at the splice.
13.2 Stiffness—The stiffness of any splice, defined as the product E times I, must provide a minimum of 100 % of pile stiffness.
For this purpose, E shall represent the Modulus of Elasticity as defined by Test Methods D6109 and I shall represent the moment
of inertia of the cross section.
13.3 Fender Piles—If at all possible, avoid placing a splice in the region of possible contact with vessels. If splices cannot be
avoided in the possible contact area, special considerations shall be taken to ensure acceptable performance and durability of the
pile under these loading conditions.
14. Specimen Conditioning
14.1 Conditioning of Specimens for Tests—Unless specifically stated otherwise, all specimens shall be conditioned and tested in
accordance with the appropriate test method.
15. Workmanship, Finish, and Appearance
15.1 The polymeric pilings furnished in accordance with this specification shall be an acceptable match to approved samples in
pattern, color, and surface appearance. The products shall be free of defects that adversely affect performance or appearance. Such
defects include, but are not limited to, blemishes, spots, indentations, cracks, blisters, and breaks.
16. Certification
16.1 When requested, a manufacturer’s certification and any other documents required to substantiate certification shall be
furnished stating that the product was manufactured to meet this specification.
17. Quality Assurance
17.1 This section presents a Quality Assurance program for the manufacturer to put into place to verify compliance with specific
portions of this specification. The program shall include the following at a minimum:
17.1.1 Product Specification, including incoming product inspection and acceptance requirements.
17.1.2 Sampling and inspection frequencies shall be devised to encompass all variables that affect the quality of the finished
product including lot-to-lot variations from different production runs. Increased frequencies shall be used in connection with new
or revised facilities. A random sampling scheme shall generally be used for specimen selection.
NOTE 9—Increased sampling and test frequencies is a useful procedure when investigating apparent data trends or adjustments in process. It is desirable
at times to deviate from a random sampling scheme while investigating effects of specific variables.
17.1.3 Procedures to be followed upon failure to meet specifications or upon out of control conditions shall be specified. Included
shall be reexamination criteria for suspect product and product rejection criteria.
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17.1.4 Finished product marking, handling, protection, and shipping requirements as they relate to the performance of the finished
product shall be defined.
17.2 Inspection Personnel—All manu
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