ASTM C1072-2010 Standard Test Method for Measurement of Masonry Flexural Bond Strength《测量砖石建筑挠性结合强度的标准试验方法》.pdf

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1、Designation: C1072 10Standard 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 num

2、ber 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 Department of Defense.1. Scope*1.1 These test methods evaluate the flexural bond strength,n

3、ormal 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 first method is the “Test Method for Laboratory-Prepared Spe

4、cimens.” 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 conditions) of a mortar product withoutrequiring the product t

5、o 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. Prisms are constructed using a jig and arebag-cured.1.1.2 T

6、he 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 quality control purposes during construction. Mortars arebatch

7、ed 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 strength of unit-mortar combinations of prisms cutfrom existing w

8、alls.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 criteria for assess-ing the bond strength values obtained using

9、 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 conversions to SI units that are provided for informationonly and

10、 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 and determine the applica-bility of regulatory limitations

11、 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 Flow Table for Use in Testsof Hydraulic CementC270 Specificat

12、ion 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 Selection, Removal, and Shipment ofManufactured Masonry Un

13、its and Masonry Specimensfrom Existing Construction2.2 Other Documents:TMS 402/ACI 530/ASCE 5 Building Code Requirementsfor Masonry Structures3NBS 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 n

14、ominal1These test methods are under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and are the direct responsibility of SubcommitteeC15.04 on Research.Current edition approved June 1, 2010. Published July 2010. Originally approvedin 1993. Last previous edition approved in 2006 a

15、s C1072 06. DOI: 10.1520/C1072-10.2For 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 to the standards Document Summary page onthe ASTM website.3Available from the Masonry

16、 Standards Joint Committee, http:/www.masonrystandards.org.4Natrella, M. G., Experimental Statistics, National Bureau of Standards Hand-book 91, U.S. Government Printing Office, Aug. 1, 1963, pp. 214.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100

17、 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.size, 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 C123

18、2.TEST METHOD FOR LABORATORY-PREPARED SPECIMENS4. Summary of Test Method4.1 This 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 volume

19、proportions and are mixed to a prescribed flow. Prisms areconstructed using a jig 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

20、This test method is intended for use in comparing thebond strengths (under the given 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 withoutreq

21、uiring the product to be tested in combination with manydifferent units.5.3 This 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

22、 volume propor-tions and are mixed to a prescribed flow. Prisms are con-structed 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), norshal

23、l it be interpreted as an indication of extent of bond forpurposes of water permeability 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

24、and shown inFig. A2.3.6.4 Mechanical Paddle-Type Mortar Mixer, of no less than0.6 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 th

25、e require-ments of Test Method C780.6.7 Bond Strength Test Apparatus, conforming 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 concretem

26、asonry units meeting the requirements of Annex A1.7.2 Mortar materials (including 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,

27、 curing, andtesting of specimens at 75 6 15F (24 6 8C).8.2 Maintain the relative 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

28、 prisms) containing a total of not less than 15mortar joints. Each prism shall have 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

29、be permitted to be used in a damp loosecondition, provided that moisture content 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 mechanica

30、l paddle-type mortar mixer.Time periods referenced below are measured from when 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. Mixmo

31、rtar for 3 min and determine flow. Once flow is recorded,return 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 the batch, mix for1 min, and determine flow. Once flow is recorded, retu

32、rn 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 exceeds 130 at any time,discard the batch.9.1.3 Immediately after mixing

33、 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 remaining portion of the mortar withoutconstructing additional mortar joints

34、.C1072 1029.1.4 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 accordance with Annex A2.9.2 Conduct bond-wrench tests on prism s

35、pecimens.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 ages other than 28 days are specified, the generalrelationship b

36、etween 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 mortar materials and units tested, includingas applicable the ma

37、nufacturers 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 weight.10.1.3 Include the following in the report:10.1.3.1 W

38、eight 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, standard deviation, and test age foreach set of test specimens to th

39、e 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 not include themin the calculation of the flexural tensile stre

40、ngth 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 failure occurred at the top or bottom of the mortarjoint, or both

41、.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 within-batchcoefficients of variation varying between 10 % an

42、d 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 method. Inter-laboratory testing is now planned to determine t

43、he 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 because no test having an accepted referencevalue is available

44、.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 batched convention-ally, and their flow is not prescribed. Prisms are construct

45、edconventionally (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 evaluate the bondstrength (under the given conditions) of a pa

46、rticular 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-unit combination under fieldconditions of fabrication and wo

47、rkmanship (but not curing).Construction field tests may be used as a quality controlmeasure to ensure that performance criteria established inpreconstruction tests are being met.13.3 Flexural bond strength determined by this test methodshall not be interpreted as the flexural bond strength of a wall

48、constructed 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 construction condi-tions, specimen size, workmanship, and curing conditions aretaken into account, the results may be used to estimat

49、e theflexural strength of a wall.14. Apparatus14.1 Mechanical Paddle-Type Mortar Mixer, of no less than0.6 ft3(18 L) capacity.14.2 Cone Penetrometer, Unit Measure, Straightedge,Spatula, Tapping Stick, and Spoon, conforming to the require-ments of Test Method C780.14.3 Bond Strength Test Apparatus, conforming to therequirements of Annex A3.5Hedstrom, E. G., Tarhini, K. M., Thomas, R. D., Dubovoy, V. S., Klingner, R.E., and Cook, R. A., “Flexural Bond Strength of Concrete Masonry Prisms UsingPortland Cement and Hydrated Lime Mortars,” Masonry Society Journal, Vol 9,No. 2, Fe