ASTM C878/C878M-22

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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: C878/C878M − 14a C878/C878M − 22
Standard Test Method for
Restrained Expansion of Shrinkage-Compensating
Concrete
This standard is issued under the fixed designation C878/C878M; 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 test method covers the determination of the expansion of concrete made with shrinkage-compensating cement.
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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.(Warning—Fresh hydraulic cementitious mixtures are caustic and may cause
chemical burns to skin and tissue upon prolonged exposure. )
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.
2. Referenced Documents
2.1 ASTM Standards:
C125 Terminology Relating to Concrete and Concrete Aggregates
C192/C192M Practice for Making and Curing Concrete Test Specimens in the Laboratory
C219 Terminology Relating to Hydraulic and Other Inorganic Cements
C490C490/C490M Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar,
and Concrete
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
C806 Test Method for Restrained Expansion of Expansive Cement Mortar
C845C845/C845M Specification for Expansive Hydraulic Cement
2.2 ACI Standards and Committee Reports:
CT ACI Concrete Terminology
223R Guide for the Use of Shrinkage-Compensating Concrete
This method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.68 on Volume
Change.
Current edition approved July 1, 2014Oct. 15, 2022. Published July 2014December 2022. Originally approved in 1978. Last previous edition approved in 2014 as
C878C878/C878M – 14.14a. DOI: 10.1520/C0878_C0878M-14A.10.1520/C0878_C0878M-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Concrete Institute (ACI), P.O. Box 9094, Farmington Hills, MI 48333-9094, http://www.concrete.org.
*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
C878/C878M − 22
3. Terminology
3.1 Terms used in this test method are defined in Terminologies C219 and C125.
NOTE 1—Additional terms not found in Terminologies C219 or C125 may be found in ACI CT.
4. Significance and Use
4.1 Since the potential for expansion, under conditions of controlled restraint, of concrete made with shrinkage-compensating
cement cannot always be satisfactorily predicted from tests of mortars made in accordance with Test Method C806, a need has been
recognized for a test method in which concrete specimens are tested.
4.2 This test method can also be adapted readily to studies of expansion involving degrees of restraint, comparisons of cements,
effects of cement contents, mixture proportions, schedules, or environmental treatments that differ from the standard procedures
prescribed by this test method.
5. Apparatus
5.1 Molds, for casting test specimens, when used in conjunction with the restraining cage described in 4.2, shall provide for
forming prisms 76 mm [3 in.] square with a gage length of 250 mm [10 in.]. The molds shall otherwise conform to the requirements
for molds in Practice C490C490/C490M, except that the stud holder, gage studs, and spacer screws described in that practice will
not be used.
5.2 Restraining Cage, consisting of a threaded low-carbon steel rod (plain or zinc-coated) with steel end plates held in place by
hex nuts as shown in Fig. 1. The hex nuts outside the cage shall be of stainless steel. Stainless steel cap nuts shall be put on each
end of the rod. When tested in tension, within the elastic range, the rod shall have a strain of 2800 kN [0.0012 6 0.0001/630 lbf]
of load (Note 2).
NOTE 2—It is intended that all rods used meet the indicated requirement for strain. When a large number of rods are obtained as a single lot, exercise
judgment as to whether or not all must be tested. The designation “10-24” is used in ordinary rods having the desired properties.
5.3 Length Comparator, conforming to and to be used in accordance with the requirements of Practice C490C490/C490M. Use
a reference bar complying with the description given in Practice C490C490/C490M. If the terminals of the comparator are fitted
with collars, they shall be such that the cap nuts on the ends of the threaded rod of the specimen do not rest on the collar during
the measuring (see Figs. 2 and 3).
5.4 Tamping Rod—The tamping rod shall be a straight steel rod, 10 mm [ ⁄8 in.] in diameter, and no less than 250 mm [10 in.]
in length, having at least the tamping end rounded to a hemispherical tip of the same diameter.
5.5 Vibrators, conforming to the requirements for external vibrators prescribed in Practice C192/C192M.
6. Test Specimen
6.1 The test specimen shall be a prism: 75 mm [3 in.] square with a gage length of 250 mm [10 in.] and an overall length (including
the length of the rod and cap nuts) of approximately 290 mm [11.5 in.]. At least three specimens shall be prepared for each test.
NOTE 3—Use of aggregates of nominal maximum size greater than 25.0 mm [1 in.] may adversely affect the test results.
7. Preparation and Assembly of Specimen Molds and Restaining Cage
7.1 Install the cap nuts firmly in place on the ends of the restraining rods using a suitable adhesive to keep them from loosening
when comparator readings are made (Note 4). The cap nuts should not be removed after the initial comparator reading of a
specimen is made. Measure the restraining cage assembly length, including the cap nuts, while it is at 23.023.0 °C 6 2 °C
9 1
[73.5[73.5 °F 6 3.5 °F]. This is to ensure it is 3030 mm 6 2 mm [11 ⁄16 in. 6 ⁄16 in.]. The measurement taken at this time is used
only to ensure that comparator readings can be made.
C878/C878M − 22
Dimensions
Measurement
in. mm
9 1
A 11 ⁄16 ± ⁄16 294 ± 1.6
B 10 254 (gage length)
C 3 76
31 1
D 2 ⁄32 ± ⁄32 75 ± 1
E 1 ⁄2 38
F 1 ⁄64 37.7
G ⁄8 10
H ⁄16 5
NOTE 1—All material is mild steel, except for stainless steel cap nuts.
FIG. 1 Restraining Cage
NOTE 4—A rapid-setting epoxy has been found suitable.
7.2 Thinly cover the edges of the restraining cage end plates that contact the sides and bottom of the mold with a heavy mineral
oil or light cup grease such as petrolatum. After assembly of the molds, place a restraining cage in each mold compartment. Seal
the contact lines between the outer sides and base plate of the molds with paraffin or micro-crystalline wax. Thinly cover the
interior faces of the molds with mineral oil and remove any oil or grease from the restraining cage rod and end plates.
8. Procedure
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