ASTM C1314-2012 Standard Test Method for Compressive Strength of Masonry Prisms《砌体棱镜抗压强度的标准试验方法》.pdf

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1、Designation: C1314 11a C1314 12Standard Test Method forCompressive Strength of Masonry Prisms1This standard is issued under the fixed designation C1314; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n

2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers procedures for masonry prism construction and testing, and procedures for determining thecompressive strength o

3、f masonry, fmt, used to determine compliance with the specified compressive strength of masonry, f m. Whenthis test method is used for research purposes, the construction and test procedures within serve as a guideline and provide controlparameters.1.2 This test method also covers procedures for det

4、ermining the compressive strength of prisms obtained from field-removedmasonry specimens.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information only and are not considered sta

5、ndard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenc

6、ed Documents2.1 ASTM Standards:2C67 Test Methods for Sampling and Testing Brick and Structural Clay TileC136 Test Method for Sieve Analysis of Fine and Coarse AggregatesC140 Test Methods for Sampling and Testing Concrete Masonry Units and Related UnitsC143/C143M Test Method for Slump of Hydraulic-Ce

7、ment ConcreteC144 Specification for Aggregate for Masonry MortarC270 Specification for Mortar for Unit MasonryC476 Specification for Grout for MasonryC780 Test Method for Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit MasonryC1019 Test Method for Sampling and Te

8、sting GroutC1093 Practice for Accreditation of Testing Agencies for MasonryC1532 Practice for Selection, Removal, and Shipment of Manufactured Masonry Units and Masonry Specimens from ExistingConstructionC1552 Practice for Capping Concrete Masonry Units, Related Units and Masonry Prisms for Compress

9、ion TestingC1587 Practice for Preparation of Field Removed Manufactured Masonry Units and Masonry Specimens for TestingE105 Practice for Probability Sampling of MaterialsE111 Test Method for Youngs Modulus, Tangent Modulus, and Chord Modulus3. Terminology3.1 Definitions:3.1.1 seta set consists of at

10、 least three prisms constructed of the same material and tested at the same age.3.2 Notations:3.2.1 f mspecified compressive strength of masonry.1 This test method is under the jurisdiction of ASTM Committee C15 on Manufactured Masonry Units and is the direct responsibility of Subcommittee C15.04 on

11、 Research.Current edition approved Dec. 1, 2011Dec. 1, 2012. Published December 2011 December 2012. Originally approved in 1995. Last previous edition approved in 2011 asC1314 11.C1314 11a. DOI: 10.1520/C1314-11A.10.1520/C1314-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org,

12、 or contact ASTM 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 intended only to provide the user of an ASTM standard an indication of what changes

13、 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 current versionof the standard as published by ASTM is to be considered the official

14、 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 States13.2.2 fmtcompressive strength of masonry.3.2.3 hpprism height.3.2.4 tpleast actual lateral dimension of prism.4

15、. Significance and Use4.1 This test method provides a means of verifying that masonry materials used in construction result in masonry that meetsthe specified compressive strength.4.2 This test method provides a means of evaluating compressive strength characteristics of in-place masonry constructio

16、nthrough testing of prisms obtained from that construction when sampled in accordance with Practice C1532. Decisions made inpreparing such field-removed prisms for testing, determining the net area, and interpreting the results of compression tests requireprofessional judgment.4.3 If this test metho

17、d is used as a guideline for performing research to determine the effects of various prism construction ortest parameters on the compressive strength of masonry, deviations from this test method shall be reported. Such research prismsshall not be used to verify compliance with a specified compressiv

18、e strength of masonry.NOTE 1The testing laboratory performing this test method should be evaluated in accordance with Practice C1093.4.3.1 Appendix X2 includes guidance information for the researcher on aspects of materials, construction, and analysis.5. Masonry Prism Construction5.1 Construct prism

19、s of units representative of those used in the construction. If units have flutes or ribs that project 12 in. (12.5mm) or more from the surface of the unit, remove those flutes or ribs by saw cutting flush with the surface of the unit at the baseof the flute or rib. When prisms are used for field qu

20、ality control or assurance, record the location in the structure that correspondsto the set of prisms constructed.NOTE 2Building codes or project specifications may require a set of prisms for a given square footage of construction. Recording the location of thestructure that corresponds to a set of

21、 prisms allows the test results to be attributed to a particular portion of the structure.5.2 Construct a set of prisms for each combination of materials and each test age at which the compressive strength of masonryis to be determined.5.3 Build each prism in an opened, moisture-tight bag large enou

22、gh to enclose and seal the completed prism. Construct prismson a flat, level base. Construct prisms in a location where they will remain undisturbed until transported for testing.5.4 Construct prisms as shown in Fig. 1 with units laid in stack bond in stretcher position. Orient units in the prism as

23、 in thecorresponding construction. At the time of prism construction, the surfaces of the units shall be free of moisture. Where thecorresponding construction is of multi-wythe masonry having wythes composed of different units or mortar, build prismsrepresentative of each different wythe and test se

24、parately.5.5 Build prisms with full-size or reduced length units. Any required saw cutting shall be performed on units prior to prismconstruction. The moisture content(s) of units used to construct prisms shall be representative of those used in construction. Prismscomposed of units that contain clo

25、sed cells shall have at least one complete cell with one full-width cross web on either end (seeFig. 2). Prisms composed of units without closed cells shall have as symmetrical a cross section as possible. The minimum lengthof prisms shall be 4 in. (100 mm).NOTE 3When using larger masonry units, exp

26、erience has shown that reducing the length of these units prior to prism construction makes theirhandling and transportation easier. Thus, these reduced length unit prisms are less likely to be damaged and are more likely to be properly capped andtested. Also, the smaller prism will be less likely t

27、o be affected by plate bending effects during testing, as described in Note 9, and will therefore providea more accurate assessment of the strength of the materials in the masonry prism. For these reasons, the use of reduced length prisms is encouraged.FIG. 1 Masonry Prism ConstructionC1314 1225.6 B

28、uild masonry prisms with full mortar beds (mortar all webs and face shells of hollow units). Use mortar representative ofthat used in the corresponding construction. Use mortar joint thickness and a method of positioning and aligning units, that arerepresentative of the corresponding construction. U

29、se mortar joints that are cut flush. For prisms to be grouted, remove mortar“fins” that protrude into the grout space.5.7 Build prisms a minimum of two units high with a height-to-thickness ratio, hp/tp , between 1.3 and 5.0.5.8 Immediately following the construction of the prism, seal the moisture-

30、tight bag around the prism.5.9 Grouted Prisms.5.9.1 When prisms are fabricated for field quality control or assurance, build prisms at the same time as the correspondingconstruction, and grout prisms when the corresponding construction is being grouted. When prisms are used for other purposes,grout

31、prisms not less than 4 h nor more than 48 h following the construction of the prisms.NOTE 4Testing of prisms may be part of a projects field quality control or assurance program. These prisms are intended to be representative of aconstructed masonry element such as a wall, column, pilaster, or beam.

32、 They are built as companions to the masonry element at a jobsite where themasonry element is site-constructed, or within a factory or shop where the element is shop-built. Prisms may also be fabricated in a laboratory for researchpurposes.5.9.2 Where the corresponding construction is to be solidly

33、grouted, solidly grout the prisms. Use grout representative of thatused in the corresponding construction. Before placing grout, remove mortar droppings from the grout space. Use groutconsolidation and reconsolidation procedures representative of those used in the construction. Place additional grou

34、t into the prismsas necessary after each consolidation. Screed off excess and finish the grout so that it is level with the top of the prism and incontact with the units at the perimeter of the grout space. Grouted prisms shall contain no reinforcement.5.9.3 Where the corresponding construction is t

35、o be partially grouted, construct two sets of prisms; grout one set solid asdescribed in 5.9.2 and leave the other set ungrouted.5.9.4 Where open-end units or prisms containing grout between similar wythes are to be grouted, use similar masonry units asforms to confine the grout during placement. Br

36、ace forms to prevent displacement during grouting. Grout as described in 5.9.2.5.9.5 Immediately following the grouting operation, reseal the moisture-tight bag around the prism.5.10 Keep all prisms from freezing. Do not disturb or move prisms for the first 48 h after construction and grouting. Keep

37、 prismsin the moisture-tight bags until 48 h prior to testing.5.11 Store an indicating maximum-minimum thermometer with the sample and record the maximum and minimumtemperatures experienced during the initial 48-h period.6. Obtaining and Transporting Masonry Prisms6.1 For field-removed masonry speci

38、mens, select and remove specimens in accordance with Practice C1532.6.2 Prior to transporting constructed prisms and field-removed masonry specimens, strap or clamp each prism or specimen toprevent damage during handling and transportation. Secure prisms and specimens to prevent jarring, bouncing, o

39、r tipping overduring transporting.6.3 Transport prisms and masonry specimens in accordance with Practice C1532.FIG. 2 Reduction of Hollow Units Prior to Prism ConstructionC1314 1236.4 For field-removed masonry specimens, after the specimens have been transported to the laboratory, obtain prisms from

40、 themasonry specimens using procedures outlined in Practice C1587.7. Curing7.1 After the initial 48 h of curing for constructed prisms, maintain the bagged prisms in an area with a temperature of 75 615F (24 6 8C). Two days prior to testing, remove the moisture-tight bags and continue storing at a t

41、emperature of 75 6 15F(24 6 8C) and a relative humidity less than 80 %.7.2 For prisms obtained from field-removed masonry, store within the laboratory at a temperature of 75 6 15F (24 6 8C) anda relative humidity less than 80 % for at least two days prior to testing.7.3 Prisms shall not be oven-drie

42、d or otherwise exposed to temperatures exceeding storage temperature requirements at any timeprior to testing.7.4 Visible moisture shall not be present on the surface of the prisms at the time of testing. Extend storage time as needed toensure dry surface conditions of the prisms at the time of test

43、ing.7.5 Test prisms at an age of 28 days or at the designated test ages. Test a set of prisms at each age. Prism age shall be determinedfrom the time of laying units for ungrouted prisms, and from the time of grouting for grouted prisms.8. Measurements and Determination of Net Area8.1 Measuring Pris

44、msAs shown in Fig. 3, measure the length and width at the edges of the top and bottom faces of the prismsto the nearest 0.05 in. (1 mm). Determine the length and width by averaging the four measurements of each dimension. Measurethe height of the prism at the center of each face to the nearest 0.05

45、in. (1 mm). Determine the height by averaging the fourmeasurements.8.1.1 For prisms obtained from field-removed masonry specimens, perform additional measurements as needed to document thecondition and dimensions of the specimen.NOTE 5Prisms obtained from field-removed masonry specimens will have ma

46、ny different sizes, shapes, and configurations. These variations are aresult of differing bonding arrangements, mortaring or joining practices, presence of reinforcement and other accessories in conjunction with the masonryin service, and of techniques used to remove the specimens from wall assembli

47、es. These variations may create non-uniform prism dimensions along itslength or in its cross-section. As such, additional measurements are often required to adequately document the condition of the prism and to communicatethat condition to readers of the test report.8.2 Net Cross-Sectional Area:8.2.

48、1 Constructed PrismsTake the net cross-sectional area of ungrouted prisms as the net cross-sectional area of masonryunits, determined by measurement or from a representative sample of units tested in accordance with Test Methods C140 forconcrete masonry and with Test Methods C67 for clay masonry. If

49、 cut units are used for prism construction, determine the netcross-sectional area from additional units cut in a similar manner. Determine net cross-sectional area of fully grouted prisms bymultiplying the length and width of the prism (see 8.1).NOTE 6Net area determined by Test Methods C140 for hollow concrete units is usually slightly different from the minimum net cross-sectional areabecause unit face shells and webs are typically tapered.8.2.1.1 Consider clay masonry units whose net cross-sectional area is at least 75 % of the gross cross-sectional