ASTM C495/C495M-12(2019)

Standard Test Method for Compressive Strength of Lightweight Insulating Concrete

SIGNIFICANCE AND USE
3.1 This test method provides standardized requirements for sampling, molding, curing, and testing lightweight insulating concretes for the purpose of determining compliance with compressive strength and density specifications.
SCOPE
1.1 This test method covers the preparation of specimens and the determination of the compressive strength of lightweight insulating concrete having an oven-dry density not exceeding 800 kg/m3  [50 lb/ft3] as determined by the procedures described herein. This test method covers the preparation and testing of molded 75 by 150-mm [3 by 6-in.] cylinders.  
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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: 14-Dec-2019
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C09 - Concrete and Concrete Aggregates
• Drafting Committee: C09.21 - Lightweight Aggregates and Concrete

Relations

• Replaces: ASTM C495/C495M-12 - Standard Test Method for Compressive Strength of Lightweight Insulating Concrete
• Effective Date: 15-Dec-2019
• Refers: ASTM C670-24a - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Feb-2024
• Refers: ASTM C670-24 - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C88/C88M-24 - Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate
• Effective Date: 01-Jan-2024
• Refers: ASTM C109/C109M-23 - Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 50 mm [2 in.] Cube Specimens)
• Effective Date: 15-Dec-2023
• Refers: ASTM C39/C39M-23 - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Dec-2023
• Refers: ASTM C617/C617M-23 - Standard Practice for Capping Cylindrical Concrete Specimens
• Effective Date: 01-Oct-2023
• Refers: ASTM C88/C88M-18 - Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate
• Effective Date: 01-Aug-2018
• Refers: ASTM C39/C39M-17b - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Aug-2017
• Refers: ASTM C39/C39M-16b - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Aug-2016
• Refers: ASTM C39/C39M-16a - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Jul-2016
• Refers: ASTM C39/C39M-14a - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Jun-2014
• Refers: ASTM C39/C39M-14 - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• Effective Date: 01-Feb-2014
• Refers: ASTM C172/C172M-14 - Standard Practice for Sampling Freshly Mixed Concrete
• Effective Date: 01-Feb-2014
• Refers: ASTM C670-13 - Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
• Effective Date: 01-Jul-2013

Overview

ASTM C495/C495M-12(2019) is the standard test method developed by ASTM International for evaluating the compressive strength of lightweight insulating concrete. This method details the proper procedures for sampling, molding, curing, and testing lightweight concrete specimens to assess their compliance with targeted strength and density specifications. The standard applies to concrete with an oven-dry density not exceeding 800 kg/m³ [50 lb/ft³], providing uniform procedures for specimen preparation and compressive strength determination.

ASTM C495/C495M-12(2019) supports the construction industry’s quality assurance practices by providing standardized guidelines, ensuring consistency, and enabling comparison of materials across projects. This international standard was developed according to principles set by the World Trade Organization Technical Barriers to Trade Committee, ensuring global relevance and acceptance.

Key Topics

• Scope and Applicability

  • Covers lightweight insulating concrete with an oven-dry density up to 800 kg/m³ (50 lb/ft³)
  • Applies to the preparation and testing of cylindrical specimens (75 by 150 mm or 3 by 6 in.)

• Sampling and Specimen Preparation

  • Includes procedures for obtaining and handling fresh samples from placement equipment
  • Specifies requirements for molding cylinders without remixing, and proper tapping to minimize air entrapment

• Curing and Conditioning

  • Details curing conditions, temperatures, and humidity to ensure reliable and reproducible results
  • Outlines separate oven-drying procedures to determine density and manage specimen moisture content

• Testing Procedure

  • Describes accurate placement, alignment, and loading rates for compressive strength testing
  • Emphasizes the importance of cap preparation, surface flatness, and symptom documentation after testing

• Reporting and Data Recording

  • Stipulates comprehensive documentation, including sample identification, density, dimensions, maximum load, and compressive strength
  • Requires reporting of curing environment, specimen age, and observations on specimen appearance

Applications

ASTM C495/C495M-12(2019) is widely utilized in the following scenarios:

• Quality Control in Construction

  • Testing of lightweight insulating concrete used in roof decks, floor fills, insulation layers, and non-structural components
  • Verification that materials meet project-specific compressive strength and density criteria before installation

• Material Development and Research

  • Assessment of new formulations or proprietary lightweight insulating concrete mixes
  • Benchmarking different materials for performance in insulation, weight, and strength

• Specification Compliance

  • Demonstrating conformance to project requirements and industry codes concerning insulation and energy efficiency
  • Supporting documentation for client reporting, regulatory submissions, and warranty purposes

• International Projects

  • Ensuring harmonized testing procedures for lightweight insulating concrete across global supply chains and construction sites

Related Standards

Organizations and professionals applying ASTM C495/C495M-12(2019) frequently reference the following standards for interconnected aspects of testing and quality assurance:

• ASTM C39/C39M - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens
• ASTM C88/C88M - Standard Test Method for Soundness of Aggregates by Use of Sodium Sulfate or Magnesium Sulfate
• ASTM C109/C109M - Test Method for Compressive Strength of Hydraulic Cement Mortars
• ASTM C172/C172M - Practice for Sampling Freshly Mixed Concrete
• ASTM C617/C617M - Practice for Capping Cylindrical Concrete Specimens
• ASTM C670 - Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials

These referenced documents build a robust framework for the reliable evaluation of lightweight insulating concrete, ensuring that all procedures align with industry best practices and regulatory expectations.

Keywords: ASTM C495/C495M-12, compressive strength, lightweight insulating concrete, concrete testing, oven-dry density, construction quality control, standard test method, concrete specimen preparation, international standards.

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: C495/C495M − 12 (Reapproved 2019)
Standard Test Method for
Compressive Strength of Lightweight Insulating Concrete
This standard is issued under the fixed designation C495/C495M; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* Hydraulic Cement Mortars (Using 2-in. or [50-mm] Cube
Specimens)
1.1 This test method covers the preparation of specimens
C172/C172M Practice for Sampling Freshly Mixed Con-
and the determination of the compressive strength of light-
crete
weight insulating concrete having an oven-dry density not
3 3 C617/C617M Practice for Capping Cylindrical Concrete
exceeding 800 kg/m [50 lb/ft ] as determined by the proce-
Specimens
dures described herein.This test method covers the preparation
C670 Practice for Preparing Precision and Bias Statements
and testing of molded 75 by 150-mm [3 by 6-in.] cylinders.
for Test Methods for Construction Materials
1.2 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
3. Significance and Use
each system may not be exact equivalents; therefore, each
3.1 This test method provides standardized requirements for
system shall be used independently of the other. Combining
sampling, molding, curing, and testing lightweight insulating
values from the two systems may result in non-conformance
concretes for the purpose of determining compliance with
with the standard.
compressive strength and density specifications.
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Apparatus
responsibility of the user of this standard to establish appro-
4.1 Testing Machine—Use a testing machine as prescribed
priate safety, health, and environmental practices and deter-
in Test Method C39/C39M.
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor- 4.2 Scales and Weights—Use scales and weights in weigh-
dance with internationally recognized principles on standard- ing specimens that conform to those specified in theApparatus
ization established in the Decision on Principles for the
Section of Test Method C109/C109M.
Development of International Standards, Guides and Recom-
4.3 Drying Oven—Use an oven as specified in Test Method
mendations issued by the World Trade Organization Technical
C88/C88M.
Barriers to Trade (TBT) Committee.
4.4 Molds—Use molds made of nonabsorbent materials or
of materials treated to reduce absorption, that are watertight,
2. Referenced Documents
and not subject to distortion of more than 2 mm [ ⁄16 in.] in any
2.1 ASTM Standards:
dimension during molding and early curing of specimens. Coat
C39/C39M Test Method for Compressive Strength of Cylin-
all mold surfaces that will be in contact with concrete except
drical Concrete Specimens
single use plastic molds with wax or mineral oil, prior to use.
C88/C88M Test Method for Soundness of Aggregates by
Use molds having a diameter of 75 62mm[3 6 ⁄16 in.] and
Use of Sodium Sulfate or Magnesium Sulfate
a length of 150 63mm[6 6 ⁄8 in.].
C109/C109M Test Method for Compressive Strength of
5. Sampling
This test method is under the jurisdiction of ASTM Committee C09 on
5.1 Sample fresh lightweight insulating concrete in accor-
Concrete and Concrete Aggregatesand is the direct responsibility of Subcommittee
dance with applicable provisions of Practice C172/C172M,
C09.21 on Lightweight Aggregates and Concrete.
with the following exceptions:
Current edition approved Dec. 15, 2019. Published December 2019. Originally
5.1.1 Sampling from Pump Equipment—Fill a bucket of
approved in 1962. Last previous edition approved in 2012 as C495/C495M–12.
DOI: 10.1520/C0495_C0495M-12R19.
approximately 9-L [10-qt] capacity by passing through the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dischargestreamoftheconcretepumphosebeingusedtoplace
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
theconcrete,atthepointofplacementoftheconcrete.Exercise
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. care to ensure that the sample is representative of the pour,
*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
C495/C495M − 12 (2019)
avoiding the beginning or ending of the discharge from the 6.7 Preparation for Testing—Check whether the surfaces of
equipment. Prepare the test specimens as described in Section the specimen that will be in contact with the bearing surfaces
6, by filling them with a scoop of lightweight insulating of the testing machine are within 0.5 mm [0.02 in.]. If the
concrete dipped from the bucket. bearing surfaces depart from a plane more than 0.5 mm [0.02
in.], grind them to conform to this tolerance or cap in
5.1.2 Remixing Sample—Do not remix the sample.
accordance with Practice C617/C617M. Cap surfaces to be
plane within 0.05 mm [0.002 in.]. Check the planeness of the
6. Test Specimens
bearing surface of the specimen by means of a straightedge and
6.1 Size and Shape—Use cylindrical test specimens 75 6 2
feeler gage, making a minimum of three measurements on
1 1
mm [3 6 ⁄16 in.] in diameter and 150 63mm[6 6 ⁄8 in.] in
different diameters of the specimen. Make sure the surface of
length, with the base of each specimen perpendicular to the
the specimen in contact with the lower bearing block of the
longitudinal axis within the limits prescribed in 6.8.
testing machine does not depart from perpendicularity with the
6.2 Number—The compressive strength of the sample shall
longitudinal axis of the cylinder by more than 1° (approxi-
be based on the average strength of four cylinders. Obtain at
mately equivalent to 2.5 mm in 150 mm [0.1 in. in 6 in.]) or the
least four test cylinders for compressive strength tests from
combined departure of the two bearing surfaces from perpen-
each sample of lightweight insulating concrete.
dicularity by more than 3°.
6.3 Molding—In molding the specimens, place the concrete
6.8 Measurement of Specimen—Determine the diameter of
in two approximately equal layers. Tap the outside of the mold
the specimens to the nearest 0.2 mm [0.01 in.] by averaging
lightly 10 to 15 times with an open hand after placing each
two diameters measured at right angles to each other at about
layer to close voids and release entrapped air. Over fill the
midheight of the specimen. Use these dimensions in computing
mold when placing the second layer. Do not rod the concrete.
the cross-sectional areas. Determine the height of the specimen
to the nearest 0.2 mm [0.01 in.]. Weigh the cylinders before
6.4 Finishing Surface—Strike off the specimens immedi-
capping and calculate the density from the measured dimen-
ately after filling the molds. Cover them in such a manner as to
3 3
sions. Record the density to the nearest 10 kg/m [0.5 lb/ft ].
prevent evaporation without marring the surface (Note 1). If
desired, cover the filled mold with a glass or metal plate to
7. Procedure
obtainasurfacethatwillbesuitablefortestingwithoutcapping
7.1 Placing of Specimen—Wipe clean the bearing faces of
and with a minimum of grinding.
the upper and lower bearing blocks of the compression test
NOTE 1—It is desirable to place the filled mold in a moist room if one
machine and of the test specimen and place the test specimen
is availab
...