1、Designation: C1072 131Standard Test Methods forMeasurement of Masonry Flexural Bond Strength1This standard is issued under the fixed designation C1072; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A nu
2、mber in parentheses indicates the year of last reapproval. Asuperscript 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.1NOTEEditorially corrected Table X1.1 in March 2014.1. Scope*1.
3、1 These test methods evaluate the flexural bond strength,normal to the bed joints, of masonry built of manufacturedmasonry units. Sampling and testing procedures are referenced,and terms are defined. Three different specimen fabricationmethods are specified, each for a different purpose:1.1.1 The fi
4、rst method is the “Test Method for Laboratory-Prepared Specimens.” Its purpose is to compare the bondstrengths (under the given conditions) of masonry mortars. Itcould be used, for example, to check the quality of mortarproducts after production, or to indicate the bond strength(under the given cond
5、itions) of a mortar product withoutrequiring the product to be tested in combination with manydifferent units. It is not intended to represent field conditions.It uses standard concrete masonry units. Mortars are batchedby weight equivalents of volume proportions and are mixed toa prescribed flow. P
6、risms are constructed using a jig and arebag-cured.1.1.2 The second method is the “Test Method for Field-Prepared Specimens.” Its purpose is to evaluate the bondstrength (under the given conditions) of a particular unit-mortarcombination, either for preconstruction evaluation of materialsor for qual
7、ity control purposes during construction. Mortars arebatched conventionally, and the flow is not prescribed. Prismsare constructed conventionally (no jig) and are bag-cured.1.1.3 The third method is the “Test Method for PrismsRemoved from Existing Masonry.” Its purpose is to evaluatethe bond strengt
8、h of unit-mortar combinations of prisms cutfrom existing walls.1.1.4 The three methods are not consistent, nor are theyintended to be. They are intended to be used for three differentpurposes. To make this clear, the three methods are presentedseparately.1.1.5 Appendix X1 suggests two possible crite
9、ria for assess-ing the bond strength values obtained using these test methods.These possible evaluation criteria are given for illustration onlyand are not mandatory.1.2 The values stated in inch-pound units are to be regardedas the standard. The values given in parentheses are mathemati-cal convers
10、ions to SI units that are provided for informationonly and are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices
11、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 andStructural Clay TileC140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related UnitsC230/C230M Specification for Flo
12、w Table for Use in Testsof Hydraulic CementC270 Specification for Mortar for Unit MasonryC780 Test Method for Preconstruction and ConstructionEvaluation of Mortars for Plain and Reinforced UnitMasonryC1232 Terminology of MasonryC1437 Test Method for Flow of Hydraulic Cement MortarC1532 Practice for
13、Selection, Removal, and Shipment ofManufactured Masonry Units and Masonry Specimensfrom Existing Construction2.2 Other Documents:TMS 402/ACI 530/ASCE 5 Building Code Requirementsfor Masonry Structures31These test methods are under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units a
14、nd are the direct responsibility of SubcommitteeC15.04 on Research.Current edition approved April 15, 2013. Published April 2013. Originallyapproved in 1993. Last previous edition approved in 2012 as C1072 12. DOI:10.1520/C1072-13E01.2For referenced ASTM standards, visit the ASTM website, www.astm.o
15、rg, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from the Masonry Standards Joint Committee, http:/www.masonrystandards.org.*A Summary of Changes section appears at
16、the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1NBS Handbook 9143. Terminology3.1 Definitions:3.1.1 lot, nmaterial of a given quantity of a single type,grade, class, and brand and practically of the same nomina
17、lsize, color range, texture, and composition produced by asingle source by virtually the same process and under essen-tially the same conditions.3.2 For additional terms used in this test method, refer toTerminology C1232.TEST METHOD FOR LABORATORY-PREPARED SPECIMENS4. Summary of Test Method4.1 This
18、 test method is for evaluating the flexural bondstrength (under the given conditions) of masonry built ofstandard masonry units. It uses standard concrete masonryunits. Mortars are batched by weight equivalents of volumeproportions and are mixed to a prescribed flow. Prisms areconstructed using a ji
19、g and are bag-cured.NOTE 1Standard fired clay masonry units are under development butare not now available. When their development is complete, they will beincorporated into these test methods.5. Significance and Use5.1 This test method is intended for use in comparing thebond strengths (under the g
20、iven conditions) of masonry mor-tars.5.2 This test method could be used, for example, to checkone aspect of the quality of mortar products after production, orto indicate the bond potential of a mortar product withoutrequiring the product to be tested in combination with manydifferent units.5.3 This
21、 test method uses controlled conditions of fabrica-tion and curing that are not intended to represent fieldconditions.5.4 This test method uses standard concrete masonry units.Mortars are batched by weight equivalents of volume propor-tions and are mixed to a prescribed flow. Prisms are con-structed
22、 using a jig and are bag-cured.5.5 Flexural bond strength determined by this test methodshall not be interpreted as the flexural bond strength of a wall(because standard units are not used for wall construction), norshall it be interpreted as an indication of extent of bond forpurposes of water perm
23、eability evaluation.6. Apparatus6.1 Prism Alignment Jig, as described in Annex A2 andshown in Fig. A2.1.6.2 Mortar Joint Template, as described in Annex A2 andshown in Fig. A2.2.6.3 Drop Hammer, as described in Annex A2 and shown inFig. A2.3.6.4 Mechanical Paddle-Type Mortar Mixer, of no less than0.
24、6 ft3(18 L) capacity.6.5 Flow Table, Flow Mold, and Caliper, conforming to therequirements of Specification C230/C230M.6.6 Cone Penetrometer, Unit Measure, Straightedge,Spatula, Tapping Stick, and Spoon, conforming to the require-ments of Test Method C780.6.7 Bond Strength Test Apparatus, conforming
25、 to the re-quirements of Annex A3.7. Materials7.1 Select representative samples of each lot of mortarmaterials. Each sample of material shall be of sufficientquantity to build a set of test prisms. Use standard concretemasonry units meeting the requirements of Annex A1.7.2 Mortar materials (includin
26、g water) shall be at an equi-librium temperature with laboratory air (see Section 8).8. Temperature and Humidity8.1 Maintain the temperature of laboratory air in the vicinityof mixing of mortar, fabrication of specimens, curing, andtesting of specimens at 75 6 15F (24 6 8C).8.2 Maintain the relative
27、 humidity of laboratory air in thevicinity of mixing of mortar, fabrication of specimens, andtesting of specimens between 30 and 80 %.9. Procedure9.1 Fabricate a set of stack-bonded test prisms (any conve-nient number of prisms) containing a total of not less than 15mortar joints. Each prism shall h
28、ave no more than 5 joints.9.1.1 Proportion mortar materials by weights equivalent tovolume proportions to be used in prism construction. Use unitweights for individual materials as given in SpecificationC270. Sand shall be permitted to be used in a damp loosecondition, provided that moisture content
29、 of sand is determinedwith reference to the oven-dried condition and batch propor-tions are adjusted accordingly. Record weight of ingredients(including water) added to the batch of mortar.9.1.2 Mix mortar in a mechanical paddle-type mortar mixer.Time periods referenced below are measured from when
30、waterand cementitious materials are combined.9.1.2.1 For standard concrete masonry units, add an esti-mated amount of water to the mortar to achieve a flow of 1276 3 determined in accordance with Test Method C1437. Mixmortar for 3 min and determine flow. Once flow is recorded,4Natrella, M. G.,Experi
31、mental Statistics, National Bureau of Standards Hand-book 91, U.S. Government Printing Office, Aug. 1, 1963, pp. 214.C1072 1312return the material used to measure flow to the mixer. If theflow is 127 6 3, continue mixing the batch for an additional 2min. If the flow is less than 124, add water to th
32、e batch, mix for1 min, and determine flow. Once flow is recorded, return thematerial used to measure flow to the mixer. If the flow is 1276 3, continue mixing the batch for 1 min.9.1.2.2 If after the one-time addition of water the flow is not127 6 3, discard the batch.9.1.2.3 If the measured flow ex
33、ceeds 130 at any time,discard the batch.9.1.3 Immediately after mixing the mortar, determine itsinitial cone penetration in accordance with Test Method C780.Determine the cone penetration of the mortar every 15 6 5min. If the cone penetration is less than 80 % of its initialvalue, discard the remain
34、ing portion of the mortar withoutconstructing additional mortar joints.9.1.4 Use standard concrete masonry units as defined inAnnex A1. Clean the bed surface of units of dirt, loose sand, orother contaminants.9.1.5 Fabricate prism specimens as described in Annex A2.9.1.6 Cure prism specimens in acco
35、rdance with Annex A2.9.2 Conduct bond-wrench tests on prism specimens.9.2.1 Test the prisms in the same facility where they werebuilt.9.2.2 Test masonry prisms in accordance with Annex A3.Determine the flexural tensile strength of each mortar jointtested, as described in Annex A3.NOTE 2When test age
36、s other than 28 days are specified, the generalrelationship between the strength at the specified test age and that at 28days is generally established by test. That relationship may vary withdifferent materials and curing conditions.10. Report10.1 Report the following information:10.1.1 Identify mor
37、tar materials and units tested, includingas applicable the manufacturers name, brand name, type,grade, source of sample, date sampled, and date tested.10.1.2 List unit and prism dimensions to the nearest 0.05 in.(1.0 mm), number of joints per prism, and number of prismsper set of specimens and prism
38、 weight.10.1.3 Include the following in the report:10.1.3.1 Weight of ingredients (including water) added tothe batch of mortar.10.1.3.2 Flow or cone penetrometer reading of mortar usedto construct prisms.10.1.3.3 Flexural bond strength test results for each joint ofthe test specimens. Mean, standar
39、d deviation, and test age foreach set of test specimens to the nearest psi.10.1.3.4 If one or more mortar joints break during thehandling of the specimen and tightening of the loading clampsbut before additional load is applied by the testing apparatus,report which joints broke prematurely but do no
40、t include themin the calculation of the flexural tensile strength average andstandard deviation. The top mortar joint shall be designatedjoint Number 1, the second, Number 2, etc. Measured loadsand calculations shall also be included.10.1.3.5 Description of failure, especially indicatingwhether fail
41、ure occurred at the top or bottom of the mortarjoint, or both.11. Precision and Bias11.1 PrecisionPublished data are not available for within-laboratory variability of this test method. Published data(Hedstrom,5Melander6) obtained under conditions almostidentical with those of this test method show
42、within-batchcoefficients of variation varying between 10 % and 25 % for30-joint samples of selected portland cement-lime mortars andmasonry cement mortars. Because only one sample of eachmortar was tested in each laboratory, sufficient data are notavailable to establish repeatability for this test m
43、ethod. Inter-laboratory testing is now planned to determine the reproduc-ibility of this test method. It is the intent of this committee todevelop precision values within five years from the date ofissuance of this test method.11.2 BiasNo information can be presented on the bias ofthis test method b
44、ecause no test having an accepted referencevalue is available.TEST METHOD FOR FIELD-PREPARED SPECIMENS12. Summary of Test Method12.1 This test method is for evaluating the flexural bondstrength (under the given conditions) of masonry built ofconventional masonry units. Mortars are batchedconventiona
45、lly, and their flow is not prescribed. Prisms areconstructed conventionally (no jig) and are bag-cured.13. Significance and Use13.1 This test method is intended for evaluation of flexuralbond strength (under the given conditions) between mortar andunits.13.2 The purpose of this test method is to eva
46、luate the bondstrength (under the given conditions) of a particular unit-mortarcombination, either for preconstruction evaluation of materialsor for quality control purposes during construction. Precon-struction field tests may be used to provide information on thepotential performance of a mortar-u
47、nit combination under fieldconditions of fabrication and workmanship (but not curing).Construction field tests may be used as a quality controlmeasure to ensure that performance criteria established inpreconstruction tests are being met.5Hedstrom, E. G., Tarhini, K. M., Thomas, R. D., Dubovoy, V. S.
48、, Klingner, R.E., and Cook, R. A., “Flexural Bond Strength of Concrete Masonry Prisms UsingPortland Cement and Hydrated Lime Mortars,” Masonry Society Journal,Vol9,No. 2, February 1991.6Melander, J. M., Ghosh, S. K., Dubovoy, V. S., Hedstrom, E. G., and Klingner,R. E., “Flexural Bond Strength of Con
49、crete Masonry Prisms Using Masonry CementMortars,” Masonry: Design and Construction, Problems and Repair, ASTM STP1180, ASTM, 1993.C1072 131313.3 Flexural bond strength determined by this test methodshall not be interpreted as the flexural bond strength of a wallconstructed of the same material, nor shall it be interpreted asan indication of extent of bond for purposes of water perme-ability evaluation. However, if effects of constructionconditions, specimen size, workmanship, and curing conditionsare taken into account, the results may be used to estimate theflexur
