ASTM C1903-24

Standard Specification for Precast Concrete Duct Bank

SCOPE
1.1 This specification includes the manufacturing requirements and installation guidelines of a precast duct bank system including polyvinyl chloride (PVC) duct enclosed in a concrete envelope. This specification also includes information relating to trenching, backfilling, plugging, and other incidentals necessary for a complete installation.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
1.3 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.

General Information

• Status: Published
• Publication Date: 31-Dec-2023
• ICS: 23.040.50 - Pipes and fittings of other materials
• ICS: 93.030 - External sewage systems
• Technical Committee: C13 - Concrete Pipe
• Drafting Committee: C13.01 - Non-Reinforced Concrete Sewer, Drain and Irrigation Pipe

Relations

• Replaces: ASTM C1903-21 - Standard Specification for Precast Concrete Duct Bank
• Effective Date: 01-Jan-2024
• Refers: ASTM A1064/A1064M-24 - Standard Specification for Carbon-Steel Wire and Welded Wire Reinforcement, Plain and Deformed, for Concrete
• Effective Date: 15-Apr-2024
• Refers: ASTM C31/C31M-24a - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Apr-2024
• Refers: ASTM C989/C989M-24 - Standard Specification for Slag Cement for Use in Concrete and Mortars
• Effective Date: 01-Feb-2024
• Refers: ASTM C231/C231M-24 - Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
• Effective Date: 01-Jan-2024
• Refers: ASTM C1609/C1609M-24 - Standard Test Method for Flexural Performance of Fiber-Reinforced Concrete (Using Beam With Third-Point Loading)
• Effective Date: 01-Jan-2024
• Refers: ASTM C31/C31M-24 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Jan-2024
• Refers: ASTM C1064/C1064M-23 - Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete
• Effective Date: 01-Dec-2023
• Refers: ASTM C31/C31M-23 - Standard Practice for Making and Curing Concrete Test Specimens in the Field
• Effective Date: 01-Jun-2023
• Refers: ASTM A1064/A1064M-22 - Standard Specification for Carbon-Steel Wire and Welded Wire Reinforcement, Plain and Deformed, for Concrete
• Effective Date: 01-Nov-2022
• Refers: ASTM C989/C989M-22 - Standard Specification for Slag Cement for Use in Concrete and Mortars
• Effective Date: 01-Jul-2022
• Refers: ASTM C231/C231M-22 - Standard Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
• Effective Date: 01-Jun-2022
• Refers: ASTM C39/C39M-21 - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Mar-2021
• Refers: ASTM C1609/C1609M-19a - Standard Test Method for Flexural Performance of Fiber-Reinforced Concrete (Using Beam With Third-Point Loading)
• Effective Date: 15-Dec-2019
• Refers: ASTM C1064/C1064M-17 - Standard Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete
• Effective Date: 01-Oct-2017

Overview

ASTM C1903-24 provides the standard specification for precast concrete duct bank systems, focusing on systems where polyvinyl chloride (PVC) duct is enclosed in a concrete envelope. This standard outlines manufacturing requirements, material properties, installation guidelines, trenching, backfilling, plugging, and other aspects essential for a complete and effective precast duct bank installation. Developed in accordance with globally recognized standardization principles, this specification is vital for ensuring product consistency, safety, and long-term performance in underground electrical and communication utilities.

Key Topics

• Manufacturing requirements: Covers the use of proper materials, mix design, admixtures, reinforcements, and PVC conduit integration for precast duct banks.
• Material properties: Details accepted materials such as cement conforming to ASTM C150/C1157, aggregates per ASTM C33, and admixtures according to ASTM standards.
• Design criteria: Sets minimum requirements for structural performance, conduit spacing, compressive strengths, and product tolerances. Mandates that design meet project-specific loads and AASHTO LRFD requirements where applicable.
• Joint integrity: Outlines specifications for concrete shear keys, gasketed and slip joints, including pressure testing and fit verification.
• Quality control and testing: Specifies personnel qualifications, compressive strength testing, thermal resistance, mandrel testing, and inspection procedures.
• Installation guidelines: Includes trench preparation, bedding, backfilling, soil evaluation, and restoration of disturbed surfaces.

Applications

Precast concrete duct banks are essential components for underground utility infrastructure. Their main applications include:

• Electrical and communication conduit protection: Encasing and protecting bundled cables and conduits in concrete for enhanced safety, mechanical protection, and long-term reliability.
• Transportation infrastructure: Used in roadway, bridge, and airport projects to organize and shield electrical and communication utilities.
• Commercial and industrial facilities: Specified for campuses, data centers, and manufacturing plants that require robust and accessible underground duct systems.
• Municipal and utility projects: Ideal for city-wide utility upgrades, reducing maintenance needs and minimizing traffic disruptions during repairs or expansions.

ASTM C1903-24 ensures standardized quality and performance, which supports efficient project delivery and regulation compliance. The specification clarifies installation best practices, such as suitable trenching methods, dewatering requirements, appropriate backfilling procedures, and marking for traceability.

Related Standards

Compliance with ASTM C1903-24 may also require reference to several associated standards to ensure material compatibility and system integrity:

• ASTM C150/C1157 - Specifications for portland and hydraulic cements
• ASTM C33 - Specification for concrete aggregates
• ASTM A615/A706 - Specifications for reinforcing steel bars
• ASTM C1619, F477 - Specifications for elastomeric seals and gaskets
• UL 651 - Standard for rigid PVC conduit and fittings
• NEMA TC-6 & 8 - PVC duct for underground installations
• NECA/NEMA 605 - Standard for installing underground nonmetallic utility duct
• AASHTO LRFD - Bridge design specifications
• IEEE 442 - Guide for thermal resistivity measurements of soils and backfill

When designing or specifying a precast concrete duct bank system, it is crucial to refer to these standards to ensure a durable, compatible, and compliant underground conduit solution.

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Keywords: precast concrete duct bank, ASTM C1903-24, PVC duct, underground utilities, concrete encasement, conduit protection, installation guidelines, underground duct systems, utility duct bank specification, precast electrical duct bank

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: C1903 − 24
Standard Specification for
Precast Concrete Duct Bank
This standard is issued under the fixed designation C1903; 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 Cores and Sawed Beams of Concrete
C138/C138M Test Method for Density (Unit Weight), Yield,
1.1 This specification includes the manufacturing require-
and Air Content (Gravimetric) of Concrete
ments and installation guidelines of a precast duct bank system
C143/C143M Test Method for Slump of Hydraulic-Cement
including polyvinyl chloride (PVC) duct enclosed in a concrete
Concrete
envelope. This specification also includes information relating
C150/C150M Specification for Portland Cement
to trenching, backfilling, plugging, and other incidentals nec-
C231/C231M Test Method for Air Content of Freshly Mixed
essary for a complete installation.
Concrete by the Pressure Method
1.2 The values stated in inch-pound units are to be regarded
C260/C260M Specification for Air-Entraining Admixtures
as standard. The values given in parentheses are mathematical
for Concrete
conversions to SI units that are provided for information only
C309 Specification for Liquid Membrane-Forming Com-
and are not considered standard.
pounds for Curing Concrete
1.3 This international standard was developed in accor-
C494/C494M Specification for Chemical Admixtures for
dance with internationally recognized principles on standard- Concrete
ization established in the Decision on Principles for the
C595/C595M Specification for Blended Hydraulic Cements
Development of International Standards, Guides and Recom- C618 Specification for Coal Ash and Raw or Calcined
mendations issued by the World Trade Organization Technical
Natural Pozzolan for Use in Concrete
Barriers to Trade (TBT) Committee. C805/C805M Test Method for Rebound Number of Hard-
ened Concrete
2. Referenced Documents
C822 Terminology Relating to Concrete Pipe and Related
Products
2.1 ASTM Standards:
C979/C979M Specification for Pigments for Integrally Col-
A615/A615M Specification for Deformed and Plain Carbon-
ored Concrete
Steel Bars for Concrete Reinforcement
C989/C989M Specification for Slag Cement for Use in
A706/A706M Specification for Deformed and Plain Low-
Concrete and Mortars
Alloy Steel Bars for Concrete Reinforcement
C1017/C1017M Specification for Chemical Admixtures for
A1064/A1064M Specification for Carbon-Steel Wire and
Use in Producing Flowing Concrete (Withdrawn 2022)
Welded Wire Reinforcement, Plain and Deformed, for
C1064/C1064M Test Method for Temperature of Freshly
Concrete
Mixed Hydraulic-Cement Concrete
C31/C31M Practice for Making and Curing Concrete Test
C1116/C1116M Specification for Fiber-Reinforced Concrete
Specimens in the Field
C1157/C1157M Performance Specification for Hydraulic
C33/C33M Specification for Concrete Aggregates
Cement
C39/C39M Test Method for Compressive Strength of Cylin-
C1602/C1602M Specification for Mixing Water Used in the
drical Concrete Specimens
Production of Hydraulic Cement Concrete
C42/C42M Test Method for Obtaining and Testing Drilled
C1609/C1609M Test Method for Flexural Performance of
Fiber-Reinforced Concrete (Using Beam With Third-Point
Loading)
This test method is under the jurisdiction of ASTM Committee C13 on
Concrete Pipe and is the direct responsibility of Subcommittee C13.01 on C1611/C1611M Test Method for Slump Flow of Self-
Non-Reinforced Concrete Sewer, Drain and Irrigation Pipe.
Consolidating Concrete
Current edition approved Jan. 1, 2024. Published January 2024. Originally
C1619 Specification for Elastomeric Seals for Joining Con-
approved in 2021. Last previous edition approved in 2021 as C1903–21. DOI:
crete Structures
10.1520/C1903-24
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 last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1903 − 24
C1812/C1812M Practice for Design of Journal Bearing Sup- 5.1.1 Cement—Cement shall conform to the requirements of
ports to be Used in Fiber Reinforced Concrete Beam Tests Specification C150/C150M or C1157/C1157M, or shall be
D5334 Test Method for Determination of Thermal Conduc- blended cement conforming to the requirements of Specifica-
tivity of Soil and Rock by Thermal Needle Probe Proce- tion C595/C595M.
dure
5.1.2 Slag Cement—Slag cement shall conform to the re-
D7957/D7957M Specification for Solid Round Glass Fiber
quirements of Specification C989/C989M.
Reinforced Polymer Bars for Concrete Reinforcement
5.1.3 Fly Ash—Fly ash shall conform to the requirements of
F477 Specification for Elastomeric Seals (Gaskets) for Join-
Class F or Class C of Specification C618.
ing Plastic Pipe
5.2 Allowable Combinations of Cementitious Materials—
2.2 Other Standards:
Any combination of cementitious materials shall be acceptable
NEMA TC-2 Standard for Electrical Polyvinyl Chloride
4 for use in the concrete if the mix meets the testing requirements
(PVC) Conduit
of Section 9 in this specification.
NEMA TC-6&8 Standard for Polyvinyl Chloride (PVC)
Plastic Utilities Duct for Underground Installations
5.3 Aggregates—Aggregates shall conform to Specification
NECA/NEMA 605 Standard for Installing Underground
C33/C33M except that the requirement for gradation shall not
Nonmetallic Utility Duct
apply.
UL 651 Standard for Schedule 40, 80, Type EB and A Rigid
5.4 Admixtures—The following admixtures and blends are
PVC Conduit and Fittings
acceptable:
IEEE 442 Guide for Thermal Resistivity Measurements of
5.4.1 Air-entraining admixture conforming to Specification
Soils and Backfill Materials
C260/C260M;
AASHTO LRFD Bridge Design Specifications
5.4.2 Chemical admixture conforming to Specification
3. Terminology
C494/C494M;
3.1 Definitions—For definitions of terms relating to precast 5.4.3 Chemical admixture for use in producing flowing
concrete conforming to Specification C1017/C1017M; and
concrete duct bank, see Terminology C822.
5.4.4 Chemical admixture or blend meeting requirements of
4. Basis of Acceptance
this standard.
4.1 Acceptance on the Basis of Proof of Design Tests,
5.5 Fibers—The use of fiber-reinforced concrete (FRC)
Material Tests, and Inspection of Manufactured Precast Duct
conforming to the requirements of Specification C1116/
Bank Sections for Visual Defects and Imperfections—
C1116M Type 1 (steel FRC), Type II (glass FRC), and Type III
Acceptability of precast duct bank sections shall be determined
(synthetic FRC) shall be permitted in precast duct bank
by such material tests as are required in Section 5 and Section
sections.
6; and by visual inspection of the finished sections to determine
5.6 Integral Color—Concrete incorporated into precast duct
conformance with the accepted design and its freedom from
bank sections to be mixed with integral red color to indicate
defects in accordance with Section 10.
electrical encasement shall meet the requirements of Specifi-
4.2 Thermal Resistance (Rho)—When required by project
cation C979/C979M.
specifications, Precast Duct Bank Sections shall be verified to
have a thermal resistivity (Rho) value no greater than specified
5.7 Water—Water used in the production of concrete shall
as tested in accordance with Test Method D5334 or IEEE 442.
be potable, or non-potable water that meets the requirements of
Test to be completed at least annually or whenever concrete
Specification C1602/C1602M.
mixture proportions or materials change.
5.8 Reinforcement—When required by manufacturer’s
4.3 Age for Acceptance—Precast duct bank sections shall be
design, reinforcement shall meet the requirements of Specifi-
considered ready for acceptance when it conforms to the
cation A615/A615M, A706/A706M, A1064/A1064M, or
requirements as indicated by the specified tests, but not before
D7957/D7957M.
design strength has been met.
NOTE 1—Typical manufacturing procedures do not require reinforce-
ment.
5. Materials
5.9 Conduit—Conduit cast into precast duct bank sections
5.1 Cementitious Materials:
shall be sized according to project requirements and meet all
material and dimensional requirements UL 651, TC-6 & 8
Schedule 40 or Type EB, except as modified below:
Available from National Electrical Manufacturers Association (NEMA), 1300
N. 17th St., Suite 900, Arlington, VA 22209, http://www.nema.org.
5.9.1 It shall be permissible to modify the bottom socket
Available from Underwriters Laboratories (UL), UL Headquarters, 333 Pfing-
dimension to match entrance dimension to allow for field fit of
sten Road, Northbrook, IL, 60062, http://www.ul.com.
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), precast sections.
445 Hoes Ln., Piscataway, NJ 08854-4141, http://www.ieee.org.
5.9.2 Conduit with modified socket dimensions shall be
Available from American Association of State Highway and Transportation
marked “Precast-EB” for use in precast concrete duct bank
Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
http://www.transportation.org. sections built to the requirements of this specification.
C1903 − 24
5.10 Gasket Material—When required by project 6.4.4 Product dimensions and tolerances.
specifications, conduit gaskets shall meet the requirements of
7. Joints
Specification C1619 Class E or Specification F477.
7.1 Conduit Shear Protection:
6. Design
7.1.1 Precast duct bank system shall be designed,
manufactured, and installed to develop adequate support at the
6.1 Precast duct bank sections shall be designed to meet
ends of the precast sections to protect the conduit from
dead load and HL93 live load requirements in accordance with
excessive shear loads induced by differential movement of
AASHTO LRFD Bridge Design Specifications or project
adjacent sections caused by design dead and live loads.
specific requirements as specified by the owner at the time of
7.1.2 At a minimum, the installed system shall be of
order.
sufficient strength to transfer a factored wheel load included in
6.2 Dimensions—Overall dimensions of precast duct bank
AASHTO HL93 design from section to section without de-
sections shall be designed to provide for the following:
flecting conduit by more than 10 % of the inside diameter.
6.2.1 Conduit Spacing:
Determination of provided strength to be performed using
6.2.1.1 From face of concrete to OD of conduit = 3 in. (76
structural analysis in accordance with AASHTO LRFD
mm) minimum. This requirement does not apply to bell
requirements, or by physical testing.
surfaces.
7.2 Conduit—Each individual conduit section cast integrally
6.2.1.2 From OD of conduit to OD of adjacent conduit = 3
into precast concrete duct bank shall meet the following:
in. (76 mm) minimum. This requirement does not apply to bell
7.2.1 End of conduit bell to be cast flush with the end
surfaces of adjacent conduit.
mating surface of the concrete section.
6.2.2 Length of Section—Laying length of a precast duct
7.2.2 End of spigot that will be inserted into the bell to
bank section, as measured from face to face parallel to the
extend from the mating surface of the precast concrete duct
center axis of the section along a given edge, shall be as shown
bank section a sufficient length to engage the bell as detailed in
on manufacturer’s product details with tolerances as defined in
the joint design provided by the manufacturer.
Section 10.
7.2.3 Joint to be provided with one of the following sealing
6.3 Material Strengths—The manufacturer shall define the
options as required by the project specifications:
following to meet the design requirements of the precast duct
7.2.3.1 Gasket Joint—Gasket joint shall be integral with bell
bank sections:
of conduit, installed in gasket groove on Spigot end of conduit,
6.3.1 Minimum Handling Compressive Strength of the
or another configuration that meets the requirements of Speci-
Concrete—(f ' ) as required by the design, but shall not be less
ci
fication C1619 or F477. Gasket joint shall meet the pressure
than 2,000 psi (13.8 MPa) or as required by the handling
test requirements of 9.7 of this standard.
devices incorporated into the section. It is not prohibited to
7.2.3.2 Slip Joint—No gasket required. Maximum centered
determine initial handling strength of a precast duct bank
annular space between bell and spigot to be no greater than
section through application of a properly correlated rebound
0.03 in. (0.8 mm).
hammer in accordance with Test Method C805/C805M.
7.2.3.3 Regardless of Joint type—minimum insertion length
6.3.2 Minimum Compressive Strength of the Concrete at
of spigot into bell to be no less than ⁄2 of the nominal conduit
Time of Delivery—(f ' ) as required by the design, but shall not
c
inside diameter or that distance where the gasket is fully
be less than 4,000 psi (25.6 MPa), to be determined in
engaged.
accordance with Test Method C39/C39M.
6.3.3 Minimum Reinforcement Yield Strength and Ultimate
8. Manufacture
Strength—(f ) and (f ), if required.
y u
8.1 Mixture:
6.3.4 Minimum Elastic Modulus of Reinforcement—(E ), if
s
8.1.1 The aggregates shall be sized, graded, proportioned,
required.
and mixed with such proportions of cementitious materials,
6.3.5 Fiber—FRC shall provide a minimum average equiva-
water, and admixtures, if any, to produce a thoroughly mixed
lent strength ratio, R , of 30 % when tested in accordance with
e3
concrete of such quality that the precast duct bank will conform
Test Method C1609/C1609M, using the roller support system
to the test and design requirements of this specification.
described in Practice C1812/C1812M. Dosage shall be as
8.1.2 Cementitious materials shall be as specified in 5.2 and
recommended by the manufacturer.
shall be added to the mix in a proportion not less than 470
3 3
NOTE 2—An R value of 30 % is chosen to correspond to 0.18 %
e3 lb/yd (280 kg/m ) unless mix designs with a lower cementi-
minimum reinforcement ratio used in typical concrete design.
tious materials content demonstrate that the quality and per-
6.4 Product Details—Precast duct bank section documenta-
formance of the precast duct bank meet the requirements of this
tion when required by owner/purchaser to define the following: specification.
6.4.1 The concrete mix design, including all materials and
8.1.3 For wetcast concrete, air content shall be as specified
admixtures within the concrete matrix. on the manufacturer’s mix design and tested in accordance
6.4.2 Area and locations of reinforcement in units of in. /ft
with Test Method C231/C231M. If air content is not specified
(mm /m), if required. on the mix design, target air content shall be 6 % (62 %).
6.4.3 Volume of fiber reinforcement, if required, in units of 8.1.4 For wetcast concrete, unit weight test shall be per-
3 3
lb/yd (kg/m ) or percent of volume of concrete. formed in accordance with Test Method C138/C138M using
C1903 − 24
the calibrated vessel from the pressure meter meeting Test 8.5.3 Sealing Compound—A sealing compound conforming
Method C231/C231M. If air content is not required as shown to the requirements of Specification C309 shall be applied and
on approved mix design, manufacturer to verify unit weight of should be left intact until the required minimum handling
concrete by another acceptable means. strength requirements are met. The concrete at the time of
application shall be within 10°F (6°C) of the ambient tempera-
8.1.5 Integral color pigment shall be included in such
quantity as to produce a sufficiently red colored concrete to ture. All surfaces shall be kept moist prior to the application of
the compounds and shall be damp when the compound is
clearly differentiate precast duct bank from standard concrete
that is not colored. Pigment shall meet the requirements of applied.
Specification C979/C979M. The owner shall have the option to 8.5.4 The manufacturer is not prohibited from combining
request a sample prior to fabrication of the precast duct bank the methods described in 8.5.1 to 8.5.3 provided the required
minimum concrete handling compressive strength is attained.
sections for use as a comparison for minimum pigment content
in the produced sections.
9. Physical Requirements
8.2 Wetcast Concrete—Concrete that does not meet the
requirements of self-consolidating concrete in accordance with 9.1 Qualifications of Testing Personnel—Manufacturing fa-
8.3 or drycast concrete in accordance with 8.4 shall meet the cility quality control personnel responsible for verification of
requirements for slump as determined in accordance with Test requirements of this standard shall hold ACI Grade I “Concrete
Method C143/C143M. The slump at time of placement shall Field Testing Technician” or ACI Level 1 “Concrete Labora-
meet the requirements of the manufacturer
...

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: C1903 − 21 C1903 − 24
Standard Specification for
Precast Concrete Duct Bank
This standard is issued under the fixed designation C1903; 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 includes the manufacturing requirements and installation guidelines of a precast duct bank system including
polyvinyl chloride (PVC) duct enclosed in a concrete envelope. This specification also includes information relating to trenching,
backfilling, plugging, and other incidentals necessary for a complete installation.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical
conversions to SI units that are provided for information only and are not considered standard.
1.3 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:
A615/A615M Specification for Deformed and Plain Carbon-Steel Bars for Concrete Reinforcement
A706/A706M Specification for Deformed and Plain Low-Alloy Steel Bars for Concrete Reinforcement
A1064/A1064M Specification for Carbon-Steel Wire and Welded Wire Reinforcement, Plain and Deformed, for Concrete
C31/C31M Practice for Making and Curing Concrete Test Specimens in the Field
C33/C33M Specification for Concrete Aggregates
C39/C39M Test Method for Compressive Strength of Cylindrical Concrete Specimens
C42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
C138/C138M Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete
C143/C143M Test Method for Slump of Hydraulic-Cement Concrete
C150/C150M Specification for Portland Cement
C231/C231M Test Method for Air Content of Freshly Mixed Concrete by the Pressure Method
C260/C260M Specification for Air-Entraining Admixtures for Concrete
C309 Specification for Liquid Membrane-Forming Compounds for Curing Concrete
C494/C494M Specification for Chemical Admixtures for Concrete
C595/C595M Specification for Blended Hydraulic Cements
C618 Specification for Coal Ash and Raw or Calcined Natural Pozzolan for Use in Concrete
C805/C805M Test Method for Rebound Number of Hardened Concrete
C822 Terminology Relating to Concrete Pipe and Related Products
This test method is under the jurisdiction of ASTM Committee C13 on Concrete Pipe and is the direct responsibility of Subcommittee C13.01 on Non-Reinforced
Concrete Sewer, Drain and Irrigation Pipe.
Current edition approved Jan. 1, 2021Jan. 1, 2024. Published January 2021January 2024. Originally approved in 2021. Last previous edition approved in 2021 as
C1903–21. DOI: 10.1520/C1903-2110.1520/C1903-24
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1903 − 24
C979/C979M Specification for Pigments for Integrally Colored Concrete
C989/C989M Specification for Slag Cement for Use in Concrete and Mortars
C1017/C1017M Specification for Chemical Admixtures for Use in Producing Flowing Concrete (Withdrawn 2022)
C1064/C1064M Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete
C1116/C1116M Specification for Fiber-Reinforced Concrete
C1157/C1157M Performance Specification for Hydraulic Cement
C1602/C1602M Specification for Mixing Water Used in the Production of Hydraulic Cement Concrete
C1609/C1609M Test Method for Flexural Performance of Fiber-Reinforced Concrete (Using Beam With Third-Point Loading)
C1611/C1611M Test Method for Slump Flow of Self-Consolidating Concrete
C1619 Specification for Elastomeric Seals for Joining Concrete Structures
C1812/C1812M Practice for Design of Journal Bearing Supports to be Used in Fiber Reinforced Concrete Beam Tests
D5334 Test Method for Determination of Thermal Conductivity of Soil and Rock by Thermal Needle Probe Procedure
D7957/D7957M Specification for Solid Round Glass Fiber Reinforced Polymer Bars for Concrete Reinforcement
F477 Specification for Elastomeric Seals (Gaskets) for Joining Plastic Pipe
2.2 Other Standards:
NEMA TC-2 Standard for Electrical Polyvinyl Chloride (PVC) Conduit
NEMA TC-6&8 Standard for Polyvinyl Chloride (PVC) Plastic Utilities Duct for Underground Installations
NECA/NEMA 605 Standard for Installing Underground Nonmetallic Utility Duct
UL 651 Standard for Schedule 40, 80, Type EB and A Rigid PVC Conduit and Fittings
IEEE 442 Guide for Thermal Resistivity Measurements of Soils and Backfill Materials
AASHTO LRFD Bridge Design Specifications
3. Terminology
3.1 Definitions—For definitions of terms relating to precast concrete duct bank, see Terminology C822.
4. Basis of Acceptance
4.1 Acceptance on the Basis of Proof of Design Tests, Material Tests, and Inspection of Manufactured Precast Duct Bank Sections
for Visual Defects and Imperfections—Acceptability of precast duct bank sections shall be determined by such material tests as are
required in Section 5 and Section 6; and by visual inspection of the finished sections to determine conformance with the accepted
design and its freedom from defects in accordance with Section 10.
4.2 Thermal Resistance (Rho)—When required by project specifications, Precast Duct Bank Sections shall be verified to have a
thermal resistivity (Rho) value no greater than specified as tested in accordance with Test Method D5334 or IEEE 442. Test to be
completed at least annually or whenever concrete mixture proportions or materials change.
4.3 Age for Acceptance—Precast duct bank sections shall be considered ready for acceptance when it conforms to the requirements
as indicated by the specified tests, but not before design strength has been met.
5. Materials
5.1 Cementitious Materials:
5.1.1 Cement—Cement shall conform to the requirements of Specification C150/C150M or C1157/C1157M, or shall be blended
cement conforming to the requirements of Specification C595/C595M.
5.1.2 Slag Cement—Slag cement shall conform to the requirements of Specification C989/C989M.
5.1.3 Fly Ash—Fly ash shall conform to the requirements of Class F or Class C of Specification C618.
The last approved version of this historical standard is referenced on www.astm.org.
Available from National Electrical Manufacturers Association (NEMA), 1300 N. 17th St., Suite 900, Arlington, VA 22209, http://www.nema.org.
Available from Underwriters Laboratories (UL), UL Headquarters, 333 Pfingsten Road, Northbrook, IL, 60062, http://www.ul.com.
Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE), 445 Hoes Ln., Piscataway, NJ 08854-4141, http://www.ieee.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.
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5.2 Allowable Combinations of Cementitious Materials—Any combination of cementitious materials shall be acceptable for use
in the concrete if the mix meets the testing requirements of Section 9 in this specification.
5.3 Aggregates—Aggregates shall conform to Specification C33/C33M except that the requirement for gradation shall not apply.
5.4 Admixtures—The following admixtures and blends are acceptable:
5.4.1 Air-entraining admixture conforming to Specification C260/C260M;
5.4.2 Chemical admixture conforming to Specification C494/C494M;
5.4.3 Chemical admixture for use in producing flowing concrete conforming to Specification C1017/C1017M; and
5.4.4 Chemical admixture or blend meeting requirements of this standard.
5.5 Fibers—The use of fiber-reinforced concrete (FRC) conforming to the requirements of Specification C1116/C1116M Type 1
(steel FRC), Type II (glass FRC), and Type III (synthetic FRC) shall be permitted in precast duct bank sections.
5.6 Integral Color—Concrete incorporated into precast duct bank sections to be mixed with integral red color to indicate electrical
encasement shall meet the requirements of Specification C979/C979M.
5.7 Water—Water used in the production of concrete shall be potable, or non-potable water that meets the requirements of
Specification C1602/C1602M.
5.8 Reinforcement—When required by manufacturer’s design, reinforcement shall meet the requirements of Specification
A615/A615M, A706/A706M, A1064/A1064M, or D7957/D7957M.
NOTE 1—Typical manufacturing procedures do not require reinforcement.
5.9 Conduit—Conduit cast into precast duct bank sections shall be sized according to project requirements and meet all material
and dimensional requirements UL 651, TC-6 & 8 Schedule 40 or Type EB, except as modified below:
5.9.1 It shall be permissible to modify the bottom socket dimension to match entrance dimension to allow for field fit of precast
sections.
5.9.2 Conduit with modified socket dimensions shall be marked “Precast-EB” for use in precast concrete duct bank sections built
to the requirements of this specification.
5.10 Gasket Material—When required by project specifications, conduit gaskets shall meet the requirements of Specification
C1619 Class E or Specification F477.
6. Design
6.1 Precast duct bank sections shall be designed to meet dead load and HL93 live load requirements in accordance with AASHTO
LRFD Bridge Design Specifications or project specific requirements as specified by the owner at the time of order.
6.2 Dimensions—Overall dimensions of precast duct bank sections shall be designed to provide for the following:
6.2.1 Conduit Spacing:
6.2.1.1 From face of concrete to OD of conduit = 3 in. (76 mm) minimum. This requirement does not apply to bell surfaces.
6.2.1.2 From OD of conduit to OD of adjacent conduit = 3 in. (76 mm) minimum. This requirement does not apply to bell surfaces
of adjacent conduit.
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6.2.2 Length of Section—Laying length of a precast duct bank section, as measured from face to face parallel to the center axis
of the section along a given edge, shall be as shown on manufacturer’s product details with tolerances as defined in Section 10.
6.3 Material Strengths—The manufacturer shall define the following to meet the design requirements of the precast duct bank
sections:
6.3.1 Minimum Handling Compressive Strength of the Concrete—(f ' ) as required by the design, but shall not be less than 2,000
ci
psi (13.8 MPa) or as required by the handling devices incorporated into the section. It is not prohibited to determine initial handling
strength of a precast duct bank section through application of a properly correlated rebound hammer in accordance with Test
Method C805/C805M.
6.3.2 Minimum Compressive Strength of the Concrete at Time of Delivery—(f ' ) as required by the design, but shall not be less
c
than 4,000 psi (25.6 MPa), to be determined in accordance with Test Method C39/C39M.
6.3.3 Minimum Reinforcement Yield Strength and Ultimate Strength—(f ) and (f ), if required.
y u
6.3.4 Minimum Elastic Modulus of Reinforcement—(E ), if required.
s
6.3.5 Fiber—FRC shall provide a minimum average equivalent strength ratio, R , of 30 % when tested in accordance with Test
e3
Method C1609/C1609M, using the roller support system described in Practice C1812/C1812M. Dosage shall be as recommended
by the manufacturer.
NOTE 2—An R value of 30 % is chosen to correspond to 0.18 % minimum reinforcement ratio used in typical concrete design.
e3
6.4 Product Details—Precast duct bank section documentation when required by owner/purchaser to define the following:
6.4.1 The concrete mix design, including all materials and admixtures within the concrete matrix.
2 2
6.4.2 Area and locations of reinforcement in units of in. /ft (mm /m), if required.
3 3
6.4.3 Volume of fiber reinforcement, if required, in units of lb/yd (kg/m ) or percent of volume of concrete.
6.4.4 Product dimensions and tolerances.
7. Joints
7.1 Concrete Shear Key:Conduit Shear Protection:
7.1.1 Precast duct bank section shall be manufactured with an integral concrete shear key of sufficient strength system shall be
designed, manufactured, and installed to develop adequate support betweenat the ends of the precast sections to protect the conduit
from excessive shear loads induced by differential movement of adjacent sections caused by anticipateddesign dead and live loads.
7.1.2 At a minimum, the integral concrete shear key installed system shall be of sufficient strength to transfer a factored wheel
load included in AASHTO HL93 design from section to section. Determination of shear key section without deflecting conduit by
more than 10 % of the inside diameter. Determination of provided strength to be performed using structural analysis in accordance
with AASHTO LRFD requirements, or by physical testing.
7.2 Conduit—Each individual conduit section cast integrally into precast concrete duct bank shall meet the following:
7.2.1 End of conduit bell to be cast flush with the end mating surface of the concrete section.
7.2.2 End of spigot that will be inserted into the bell to extend from the mating surface of the precast concrete duct bank section
a sufficient length to engage the bell as detailed in the joint design provided by the manufacturer.
7.2.3 Joint to be provided with one of the following sealing options as required by the project specifications:
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7.2.3.1 Gasket Joint—Gasket joint shall be integral with bell of conduit, installed in gasket groove on Spigot end of conduit, or
another configuration that meets the requirements of Specification C1619 or F477. Gasket joint shall meet the pressure test
requirements of 9.7 of this standard.
7.2.3.2 Slip Joint—No gasket required. Maximum centered annular space between bell and spigot to be no greater than 0.03 in.
(0.8 mm).
7.2.3.3 Regardless of Joint type—minimum insertion length of spigot into bell to be no less than ⁄2 of the nominal conduit inside
diameter or that distance where the gasket is fully engaged.
8. Manufacture
8.1 Mixture:
8.1.1 The aggregates shall be sized, graded, proportioned, and mixed with such proportions of cementitious materials, water, and
admixtures, if any, to produce a thoroughly mixed concrete of such quality that the precast duct bank will conform to the test and
design requirements of this specification.
8.1.2 Cementitious materials shall be as specified in 5.2 and shall be added to the mix in a proportion not less than 470 lb/yd (280
kg/m ) unless mix designs with a lower cementitious materials content demonstrate that the quality and performance of the precast
duct bank meet the requirements of this specification.
8.1.3 For wetcast concrete, air content shall be as specified on the manufacturer’s mix design and tested in accordance with Test
Method C231/C231M. If air content is not specified on the mix design, target air content shall be 6 % (62 %).
8.1.4 For wetcast concrete, unit weight test shall be performed in accordance with Test Method C138/C138M using the calibrated
vessel from the pressure meter meeting Test Method C231/C231M. If air content is not required as shown on approved mix design,
manufacturer to verify unit weight of concrete by another acceptable means.
8.1.5 Integral color pigment shall be included in such quantity as to produce a sufficiently red colored concrete to clearly
differentiate precast duct bank from standard concrete that is not colored. Pigment shall meet the requirements of Specification
C979/C979M. The owner shall have the option to request a sample prior to fabrication of the precast duct bank sections for use
as a comparison for minimum pigment content in the produced sections.
8.2 Wetcast Concrete—Concrete that does not meet the requirements of self-consolidating concrete in accordance with 8.3 or
drycast concrete in accordance with 8.4 shall meet the requirements for slump as determined in accordance with Test Method
C143/C143M. The slump at time of placement shall meet the requirements of the manufacturer’s mix design and be between 1
in. (25 mm) and 8 in. (203 mm). This test shall be performed at least on the first (2) batches of a production shift or until desired
slump is achieved. Retest if changes in concrete consistency are noticed.
8.3 Self-Consolidating Concrete—When SCC is used to produce precast duct bank sections, Test Method C1611/C1611M (slump
flow of self-consolidating concrete) shall be used in place of Test Method C143/C143M (slump of hydraulic-cement concrete). This
test shall be performed at least on the first (2) batches of a production shift or until desired spread and visual stability index are
achieved. Retest if changes in concrete consistency are noticed. Target flow and visual stability index shall meet requirements
specified on the manufacturer’s mix design meeting Test Method C1611/C1611M requirements.
8.4 Drycast Con
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