1、Designation: C 1314 07Standard Test Method forCompressive Strength of Masonry Prisms1This standard is issued under the fixed designation C 1314; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in
2、 parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers procedures for masonry prismconstruction and testing, and procedures for determining thecompressive strength of masonr
3、y, fmt, used to determinecompliance with the specified compressive strength of ma-sonry, f 8m. When this test method is used for researchpurposes, the construction and test procedures within serve asa guideline and provide control parameters.1.2 This test method also covers procedures for determinin
4、gthe compressive strength of prisms obtained from field-removed masonry specimens.1.3 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are forinformation only.1.4 This standard does not purport to address all of thesafety concerns, if any, asso
5、ciated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C67 Test Methods for Sampling and Testing Brick andStruct
6、ural Clay TileC 136 Test Method for Sieve Analysis of Fine and CoarseAggregatesC 140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC 143/C 143M Test Method for Slump of Hydraulic-Cement ConcreteC 144 Specification for Aggregate for Masonry MortarC 270 Specification for
7、 Mortar for Unit MasonryC 476 Specification for Grout for MasonryC 780 Test Method for Preconstruction and ConstructionEvaluation of Mortars for Plain and Reinforced UnitMasonryC 1019 Test Method for Sampling and Testing GroutC 1093 Practice for Accreditation of Testing Agencies forMasonryC 1532 Pra
8、ctice for Selection, Removal, and Shipment ofManufactured Masonry Units and Masonry Specimensfrom Existing ConstructionC 1552 Practice for Capping Concrete Masonry Units, Re-lated Units and Masonry Prisms for Compression TestingC 1587 Practice for Preparation of Field Removed Manu-factured Masonry U
9、nits and Masonry Specimens for Com-pressive Strength TestingE 105 Practice for Probability Sampling Of MaterialsE 111 Test Method for Youngs Modulus, Tangent Modulus,and Chord Modulus3. Terminology3.1 Definitions:3.1.1 seta set consists of at least three prisms constructedof the same material and te
10、sted at the same age.3.2 Notations:3.2.1 f 8mspecified compressive strength of masonry.3.2.2 fmtcompressive strength of masonry.3.2.3 hpprism height.3.2.4 tpleast actual lateral dimension of prism.4. Significance and Use4.1 This test method provides a means of verifying thatmasonry materials used in
11、 construction result in masonry thatmeets the specified compressive strength.4.2 This test method provides a means of evaluating com-pressive strength characteristics of in-place masonry construc-tion through testing of prisms obtained from that constructionwhen sampled in accordance with Practice C
12、 1532. Decisionsmade in preparing such field-removed prisms for testing,determining the net area, and interpreting the results ofcompression tests require professional judgment.4.3 If this test method is used as a guideline for performingresearch to determine the effects of various prism constructio
13、nor test parameters on the compressive strength of masonry,deviations from this test method shall be reported. Such1This test method is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsibility of SubcommitteeC15.04 on Research.Current edition approve
14、d June 1, 2007. Published August 2007. Originallyapproved in 1995. Last previous edition approved in 2003 as C 1314 03b.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer
15、 to the standards Document Summary page onthe ASTM website.1*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.research prisms shall not be used to verify compliance with
16、aspecified compressive strength of masonry.NOTE 1The testing laboratory performing this test method should beevaluated in accordance with Practice C 1093.4.3.1 Appendix X2 includes guidance information for theresearcher on aspects of materials, construction, and analysis.5. Masonry Prism Constructio
17、n5.1 Construct prisms of units representative of those used inthe construction. If units have flutes or ribs that project12 in.(12.5 mm) or more from the surface of the unit, remove thoseflutes or ribs by saw cutting flush with the surface of the unitat the base of the flute or rib.5.2 Construct a s
18、et of prisms for each combination ofmaterials and each test age at which the compressive strengthof masonry is to be determined.5.3 Build each prism in an opened, moisture-tight bag largeenough to enclose and seal the completed prism. Constructprisms on a flat, level base. Construct prisms in a loca
19、tionwhere they will remain undisturbed until transported fortesting.5.4 Construct prisms as shown in Fig. 1 with units laid instack bond in stretcher position. Orient units in the prism as inthe corresponding construction. At the time of prism construc-tion, the surfaces of the units shall be free o
20、f moisture. Wherethe corresponding construction is of multi-wythe masonryhaving wythes composed of different units or mortar, buildprisms representative of each different wythe and test sepa-rately.5.5 Build prisms with full-size or reduced length units. Anyrequired saw cutting shall be performed on
21、 units prior to prismconstruction. The moisture content(s) of units used to constructprisms shall be representative of those used in construction.Prisms composed of units that contain closed cells shall have atleast one complete cell with one full-width cross web on eitherend (see Fig. 2). Prisms co
22、mposed of units without closed cellsshall have as symmetrical a cross section as possible. Theminimum length of prisms shall be 4 in. (100 mm).NOTE 2When using larger masonry units, experience has shown thatreducing the length of these units prior to prism construction makes theirhandling and transp
23、ortation easier. Thus, these reduced length unit prismsare less likely to be damaged and are more likely to be properly cappedand tested. Also, the smaller prism will be less likely to be affected byplate bending effects during testing, as described in Note 7, and willtherefore provide a more accura
24、te assessment of the strength of thematerials in the masonry prism. For these reasons, the use of reducedlength prisms is encouraged.5.6 Build masonry prisms with full mortar beds (mortar allwebs and face shells of hollow units). Use mortar representa-tive of that used in the corresponding construct
25、ion. Use mortarjoint thickness and a method of positioning and aligning units,that are representative of the corresponding construction. Usemortar 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
26、with aheight-to-thickness ratio, hp/tp, between 1.3 and 5.0.5.8 Immediately following the construction of the prism,seal the moisture-tight bag around the prism.5.9 Grouted Prisms.5.9.1 Where the corresponding construction is to be solidlygrouted, solidly grout the prisms not less than 24 h nor more
27、than 48 h following the construction of the prisms. Use groutrepresentative of that used in the corresponding construction.Before placing grout, remove mortar droppings from the groutspace. Use grout consolidation and reconsolidation proceduresrepresentative of those used in the construction. Place
28、addi-tional grout into the prisms as necessary after each consolida-tion. Screed off excess and finish the grout so that it is levelwith the top of the prism and in contact with the units at theperimeter of the grout space. Grouted prisms shall contain noreinforcement.FIG. 1 Masonry Prism Constructi
29、onFIG. 2 Reduction of Hollow Units Prior to Prism ConstructionC13140725.9.2 Where the corresponding construction is to be par-tially grouted, construct two sets of prisms; grout one set solidas described in 5.9.1 and leave the other set ungrouted.5.9.3 Where open-end units or prisms containing grout
30、between similar wythes are to be grouted, use similar masonryunits as forms to confine the grout during placement. Braceforms to prevent displacement during grouting. Grout asdescribed in 5.9.1.5.9.4 Immediately following the grouting operation, resealthe moisture-tight bag around the prism.5.10 Kee
31、p all prisms from freezing. Do not disturb or moveprisms for the first 48 h after construction and grouting. Keepprisms in the moisture-tight bags until 48 h prior to testing.5.11 Store an indicating maximum-minimum thermometerwith the sample and record the maximum and minimumtemperatures experience
32、d during the initial 48-h period.6. Obtaining and Transporting Masonry Prisms6.1 For field-removed masonry specimens, select and re-move specimens in accordance with Practice C 1532.6.2 Prior to transporting constructed prisms and field-removed masonry specimens, strap or clamp each prism orspecimen
33、 to prevent damage during handling and transporta-tion. Secure prisms and specimens to prevent jarring, bounc-ing, or tipping over during transporting.6.3 Transport prisms and masonry specimens in accordancewith Practice C 1532.6.4 For field-removed masonry specimens, after the speci-mens have been
34、transported to the laboratory, obtain prismsfrom the masonry specimens using procedures outlined inPractice C 1587.7. Curing7.1 After the initial 48 h of curing for constructed prisms,maintain the bagged prisms in an area with a temperature of 756 15F (24 6 8C). Two days prior to testing, remove the
35、moisture-tight bags and continue storing at a temperature of 756 15F (24 6 8C) and a relative humidity less than 80 %.7.2 For prisms obtained from field-removed masonry, storewithin the laboratory at a temperature of 75 6 15F (24 6 8C)and a relative humidity less than 80 % for at least two daysprior
36、 to testing.7.3 Prisms shall not be oven-dried or otherwise exposed totemperatures exceeding storage temperature requirements atany time prior to testing.7.4 Visible moisture shall not be present on the surface ofthe prisms at the time of testing. Extend storage time as neededto ensure dry surface c
37、onditions of the prisms at the time oftesting.7.5 Test prisms at an age of 28 days or at the designated testages. Test a set of prisms at each age. Prism age shall bedetermined from the time of laying units for ungrouted prisms,and from the time of grouting for grouted prisms.8. Measurements and Det
38、ermination of Net Area8.1 Measuring PrismsAs shown in Fig. 3, measure thelength and width at the edges of the top and bottom faces of theprisms to the nearest 0.05 in. (1 mm). Determine the length andwidth by averaging the four measurements of each dimension.Measure the height of the prism at the ce
39、nter of each face to thenearest 0.05 in. (1 mm). Determine the height by averaging thefour measurements.8.1.1 For prisms obtained from field-removed masonryspecimens, perform additional measurements as needed todocument the condition and dimensions of the specimen.NOTE 3Prisms obtained from field-re
40、moved masonry specimens willhave many different sizes, shapes, and configurations. These variations area result of differing bonding arrangements, mortaring or joining practices,presence of reinforcement and other accessories in conjunction with themasonry in service, and of techniques used to remov
41、e the specimens fromwall assemblies. These variations may create non-uniform prism dimen-sions along its length or in its cross-section. As such, additional measure-ments are often required to adequately document the condition of theprism and to communicate that condition to readers of the test repo
42、rt.8.2 Net Cross-Sectional Area:8.2.1 Constructed PrismsTake the net cross-sectional areaof ungrouted prisms as the net cross-sectional area of masonryunits, determined by measurement or from a representativesample of units tested in accordance with Test Methods C 140for concrete masonry and with Te
43、st Methods C67 for claymasonry. If cut units are used for prism construction, determinethe net cross-sectional area from additional units cut in asimilar manner. Determine net cross-sectional area of fullygrouted prisms by multiplying the length and width of theprism (see 8.1).NOTE 4Net area determi
44、ned by Test Methods C 140 for hollowconcrete units is usually slightly different from the minimum net cross-sectional area because 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 areaas 1
45、00 % solid.8.2.2 Prisms Obtained from Field-Removed MasonrySpecimensUse methods identified above to determine netarea if appropriate. Net area for prisms obtained from field-removed masonry specimens is considered to be minimumbearing area. If prisms are not of uniform length or widththroughout the
46、height of the specimen, or if mortared surfacesFIG. 3 Prism Measurement LocationC1314073are not fully bedded, use professional judgment to determinethe minimum bearing area that exists for the prism at whateverlocation that occurs.NOTE 5While constructed prisms are required to be fully-bedded withmo
47、rtar, prisms obtained from field-removed masonry specimens, particu-larly for hollow masonry, will often have only the face shells of the hollowunits mortared. For such prisms, if any mortar on the top and bottombearing surfaces of the prisms are removed to result in full bearing acrossthe unit cros
48、s-section, the minimum cross-section will typically occur atan intermediate mortar bed joint. For face shell bedded sections, multi-plying the measured length of the prism at the bed joint location by thesum of the face shell thicknesses can be an effective method fordetermining minimum net bearing
49、area. Because the face shells of hollowunits are often tapered, the thickness of the face shell above the mortar bedjoint and below the mortar bed joint may differ. In such a case, use theleast face shell thickness of the two in the calculation. Obtaining access tomeasure face shell thickness is often difficult or impossible. Measure-ments of similar cross-sections from representative units or other parts ofthe prism is an option as is performing measurements after testing isperformed. Refer to Test Methods C67 and C 140 for recommendedmethods of measuring face s
