1、Designation: C873/C873M 10aC873/C873M 15Standard Test Method forCompressive Strength of Concrete Cylinders Cast in Placein Cylindrical Molds1This standard is issued under the fixed designation C873/C873M; the number immediately following the designation indicates the yearof original adoption or, in
2、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 strength of cylindrical concrete speci
3、mens that have been molded in placeusing special molds attached to formwork. This test method is limited to use in slabs where the depth of concrete is from 125 to300 mm 5 to 12 in.1.2 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard. The values
4、 statedin each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining valuesfrom 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
5、its use. It is the responsibilityof the user of this standard to consult and establish appropriate safety and health practices and determine the applicability ofregulatory limitations prior to use. (WarningFresh hydraulic cementitious mixtures are caustic and may cause chemical burnsto skin and tiss
6、ue upon prolonged exposure.2)2. Referenced Documents2.1 ASTM Standards:3C39/C39M Test Method for Compressive Strength of Cylindrical Concrete SpecimensC42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of ConcreteC470/C470M Specification for Molds for Forming Concrete Test
7、Cylinders VerticallyC617 Practice for Capping Cylindrical Concrete SpecimensC670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction MaterialsC1231/C1231M Practice for Use of Unbonded Caps in Determination of Compressive Strength of Hardened Concrete Cylinders3. Su
8、mmary of Test Method3.1 A concrete cylinder mold assembly consisting of a mold and a tubular support member is fastened within the concreteformwork prior to placement of the concrete as shown in Fig. 1. The elevation of the mold upper edge is adjusted to correspondto the level of the finished slab s
9、urface. The mold support prevents direct contact of the slab concrete with the outside of the moldand permits easy removal of the mold from the slab. The mold is filled at the time its location is reached in the normal course ofconcrete placement. The specimen in the “cured-in-place” condition is re
10、moved from its in-place location immediately prior tode-molding, capping, and testing. The reported compressive strength is corrected on the basis of specimen length-diameter ratiousing correction factors provided in the section on calculation of Test Method C42/C42M.4. Significance and Use4.1 Cast-
11、in-place cylinder strength relates to the strength of concrete in the structure due to the similarity of curing conditionsbecause the cylinder is cured within the slab. However, due to differences in moisture condition, degree of consolidation, specimensize, and length-diameter ratio, there is not a
12、 unique relationship between the strength of cast-in-place cylinders and cores of the1 This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregatesand is the direct responsibility of Subcommittee C09.61 onTesting for Strength.Current edition approved Dec. 15,
13、2010Dec. 1, 2015. Published January 2011February 2016. Originally approved in 1977. Last previous edition approved in 2010 asC873/C873M10.10a. DOI: 10.1520/C0873_C0873M-10a.10.1520/C0873_C0873M-15.2 Section on Safety Precautions, Manual of Aggregate and Concrete Testing, Annual Book of ASTM Standard
14、s, Vol 04.02.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is int
15、ended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit 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 curr
16、ent versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1same age. When cores can be dri
17、lled undamaged and tested in the same moisture condition as the cast-in-place cylinders, thestrength of the cylinders can be expected to be on average 10 % higher than the cores at ages up to 91 days for specimens of thesame size and length-diameter ratio.44.2 Strength of cast-in-place cylinders may
18、 be used for various purposes, such as estimating the load-bearing capacity of slabs,determining the time of form and shore removal, and determining the effectiveness of curing and protection.4 Bloem, D. L., “Concrete Strength in Structures,” Journal of the American Concrete Institute, JACIA, March
19、1968, or ACI Proceedings, PACIA, Vol. 65, No. 3, pp.169248.FIG. 1 Schematic of Cast-in-Place Cylinder Mold AssemblyC873/C873M 1525. Apparatus5.1 Cast-in-place molds shall have a diameter at least three times the nominal maximum aggregate size. The length-diameterratio (L/D) of the specimen after cap
20、ping shall not be less than 1.0 (see Note 1). Molds (inner member) shall be constructed in onepiece in the form of right circular cylinders at least 100 mm 4 in. in inside diameter with the average diameter not differing fromthe nominal diameter by more than 1 % and no individual diameter differing
21、from any other diameter by more than 2 %. The planeof the rim of the mold and the bottom shall be perpendicular to the axis of the mold within 0.5 (approximately equivalent to 1mm in 300 mm 18 in. in 12 in.).NOTE 1The length-diameter ratio should preferably be between 1.5 and 2.0.5.2 Molds shall be
22、watertight and meet the criteria of the section on water leakage of Specification C470/C470M. Molds andauxiliary apparatus shall be made of nonabsorbent material that does not react with concrete containing portland or other hydrauliccements. TheyMolds shall be sufficiently strong and tough to permi
23、t use under normal construction conditions without tearing,crushing, or otherwise deforming permanently when filled with fresh concrete. TheyMolds shall resist permanent deformation tothe extent that they produce hardened concrete cylinders such that two diameters measured at right angles to each ot
24、her in anyhorizontal plane do not differ by more than 2.0 mm 116 in.5.3 The exterior top of the mold shall have outwardly extending centering knobs and an annular flange to rest on top of thesupport member (5.4) and to seal the annular ring space between the mold and that support member. Means for t
25、wisting and verticalwithdrawal of molds from the support member shall be provided in the annular flange (see Fig. 1).5.4 Support members shall be right circular cylinders and shall be rigid tubes of diameter required to accommodate moldsstipulated in 5.1 and to concentrically contact and support the
26、 annular flange of the mold. Support members shall be provided witha means for height adjustment and shall be fitted with exterior means to permit nailing or other firm attachment to slab forms ina manner preventing entry of concrete or mortar into the annular ring space between the support member a
27、nd the mold.6. Installation of Apparatus6.1 After completion of reinforcing steel placement and other formwork preparation, fasten the support member to slab formsusing nails or screws. Adjust the support member so that the top of the mold is aligned with the elevation of screed guides usedin striki
28、ng off the concrete.NOTE 2The location of mold assemblies should be noted on project drawings for easy location after concrete placement and for identification.6.2 Place the mold in the support member so that the flange of the mold is uniformly supported by the sleeve to prevent concreteor mortar fr
29、om penetrating into the space between the mold and support member.NOTE 3Insertion of compressible material between the support member and the mold is permitted to prevent mortar seepage into the annular space.7. Procedure7.1 Inspect the molds to ensure they are clean and free of any debris or foreig
30、n matter. Fill the molds when the concreteplacement progresses to the vicinity of mold location.7.2 ConsolidationConsolidate concrete in the mold to simulate the conditions of placement. In normal field constructionpractice, if the surrounding concrete is consolidated by internal vibration, use the
31、vibrator externally, briefly touching the exteriorof the mold support member. Internal vibration of concrete in the mold is prohibited except under special circumstances that shallbe explained in the report of test results. Subject the specimen surface to the same finishing as the surrounding concre
32、te.7.3 Curing of SpecimensSubject the specimens to the same curing and treatment as provided to the surrounding concrete.Record maximum and minimum slab surface temperatures during the curing period for inclusion in the report. Specimen moldsshall remain fully seated in place until time of removal f
33、or transportation to the testing location.7.4 Mold RemovalRemove molds from support members, exercising care so as not to physically damage specimens. From thetime of removal from the structure until time of test, maintain test specimens at a temperature within 65 C 610 F of the slabsurface temperat
34、ure at the time of removal. Transport specimens to the laboratory within 4 h after removal. During transportationprotect the specimens with suitable material to prevent damage from jarring, to insulate them from extreme ambient temperatures,and to prevent moisture loss.7.5 Testing of SpecimensRemove
35、 specimens from molds. Determine the average diameter of each specimen to the nearest 0.2mm 0.01 in. by averaging two diameters measured at right angles to each other at about the midheight of the specimen. Capspecimens in accordance with Practice C617 and measure the length of the capped specimens
36、to the nearest 2 mm 0.1 in.Alternatively, measure the length of the specimens to the nearest 2 mm 0.1 in. and use unbonded caps in accordance with PracticeC1231/C1231M. Test the specimens in accordance with Test Method C39/C39M. Test the specimens for compressive strength inthe “as-received” moistur
37、e condition unless required otherwise by project specifications.C873/C873M 1538. Calculation8.1 Calculate the compressive strength of each specimen using the computed cross-sectional area based on the average diameterof the specimen. If the length-diameter ratio of the specimen is 1.75 or less, corr
38、ect the calculated strength by multiplying by theapplicable strength correction factor given in Test Method C42/C42M.9. Report9.1 Report the following information:9.1.1 Identification of structure in which specimens were cast, identification of specimen, and location of the mold in thestructure,9.1.
39、2 Diameter and length, mm in.,9.1.3 Maximum load, N lbf,9.1.4 The L/D strength correction factor used,9.1.5 Compressive strength calculated to the nearest 10 psi 0.1 MPa after multiplying by the applicable L/D strength correctionfactor, if required,9.1.6 Type of fracture (see Test Method C39/C39M),9
40、.1.7 Defects in specimen, or caps, if observed,9.1.8 Age of specimen,9.1.9 Curing methods used,9.1.10 Initial concrete temperature,9.1.11 Maximum and minimum temperature information obtained at job site to define curing conditions of specimens in place,9.1.12 Detailed descriptions of any internal vi
41、bration or other internal manipulations of the fresh concrete in the mold (7.2), and9.1.13 Other information pertaining to job conditions that could affect the results.10. Precision and Bias10.1 PrecisionThe single-operator coefficient of variation has been found to be 3.5 %5 for a range of compress
42、ive strengthbetween 10 and 41 MPa 1500 and 6000 psi.6 Therefore, results of two properly conducted tests by the same operator on the samesample of concrete should not differ from each other by more than 10.0 %5 of their average. Larger differences may be due toimproperly prepared specimens or actual
43、 strength differences because of different batches of concrete or different curingconditions.10.2 BiasThe bias of this test method cannot be determined because the strength of a cast-in-place cylindrical specimen canonly be obtained by using this test method.11. Keywords11.1 compressive strength; co
44、ncrete; cylinder molds ; in-place strengthSUMMARY OF CHANGESCommittee C09 has identified the location of selected changes to this test method since the last issue,C873/C873M10,10a, that may impact the use of this test method. (Approved Dec. 1, 2015December 15,2010.).)(1) Revised 7.2 to eliminate non
45、-mandatory language.(1) Section 5.2 was revised.5 These numbers represent, respectively, the (1s %) and (d2s %) limits as described in Practice C670.6 This statement was derived from research data reported by Nicholas J. Carino, H. S. Lew, and Charles K. Volz in “Early Age Temperature Effects on Con
46、crete StrengthPrediction by the Maturity Method,” ACI Journal, Vol 80, No. 2, MarchApril 1983.C873/C873M 154(2) Revised the temperature range in SI units in 7.4 to a more rational value and clarified the needs for protection duringtransportation.Committee C09 has identified the location of selected
47、changes to this test method since the last issue,C873/C873M041, that may impact the use of this test method. (Approved June 15, 2010.)(1) The order of the inch-pound and SI units was reversed.(2) Minor revisions were made to 3.1 to improve clarity.(3) Minor revisions were made to 4.1 to clarify the
48、intent of the second sentence.(4)Anew Note 1 was added to remove non-mandatory text from the body of the standard and subsequent notes were renumbered.(5) A minor revision was made to 5.2 to clarify that the intent is to prevent permanent distortion of the molds.(6) Additional text was added to 5.3
49、to clarify how the molds are used.(7) In 5.4, the reference to attaching molds to reinforcing steel was removed because this is not done in practice.(8) Minor changes were made to 6.1 and the last sentence was moved to a new Note 2.(9) 7.5 was revised to permit the use of unbonded caps.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent ri
