1、Designation: C1072 12C1072 13Standard 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 revisio
2、n. A number 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 st
3、rength, normal to the bed joints, of masonry built of manufactured masonryunits. Sampling and testing procedures are referenced, and terms are defined. Three different specimen fabrication methods arespecified, each for a different purpose:1.1.1 The first method is the “Test Method for Laboratory-Pr
4、epared Specimens.” Its purpose is to compare the bond strengths(under the given conditions) of masonry mortars. It could be used, for example, to check the quality of mortar products afterproduction, or to indicate the bond strength (under the given conditions) of a mortar product without requiring
5、the product to betested in combination with many different units. It is not intended to represent field conditions. It uses standard concrete masonryunits. Mortars are batched by weight equivalents of volume proportions and are mixed to a prescribed flow. Prisms are constructedusing a jig and are ba
6、g-cured.1.1.2 The second method is the “Test Method for Field-Prepared Specimens.” Its purpose is to evaluate the bond strength (underthe given conditions) of a particular unit-mortar combination, either for preconstruction evaluation of materials or for qualitycontrol purposes during construction.
7、Mortars are batched conventionally, and the flow is not prescribed. Prisms are constructedconventionally (no jig) and are bag-cured.1.1.3 The third method is the “Test Method for Prisms Removed from Existing Masonry.” Its purpose is to evaluate the bondstrength of unit-mortar combinations of prisms
8、cut from existing walls.1.1.4 The three methods are not consistent, nor are they intended to be. They are intended to be used for three different purposes.To make this clear, the three methods are presented separately.1.1.5 Appendix X1 suggests two possible criteria for assessing the bond strength v
9、alues obtained using these test methods.These possible evaluation criteria are given for illustration only and are not mandatory.1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are mathematicalconversions to SI units that are provided for
10、 information only and are not considered standard.1.3 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 re
11、gulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C67 Test Methods for Sampling and Testing Brick and Structural Clay TileC140 Test Methods for Sampling and Testing Concrete Masonry Units and Related UnitsC230/C230M Specification for Flow Table for Use in Tests of Hydraulic
12、 CementC270 Specification for Mortar for Unit MasonryC780 Test Method for Preconstruction and Construction Evaluation of Mortars for Plain and Reinforced Unit MasonryC1232 Terminology of MasonryC1437 Test Method for Flow of Hydraulic Cement Mortar1 These test methods are under the jurisdiction of AS
13、TM Committee C15 on Manufactured Masonry Units and are the direct responsibility of Subcommittee C15.04 onResearch.Current edition approved Dec. 1, 2012April 15, 2013. Published December 2011 April 2013. Originally approved in 1993. Last previous edition approved in 20112012as C1072 11.C1072 12. DOI
14、: 10.1520/C1072-12.10.1520/C1072-13.2 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 A
15、STM standard and is intended 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
16、all cases only the current 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 States1C1532 Pr
17、actice for Selection, Removal, and Shipment of Manufactured Masonry Units and Masonry Specimens from ExistingConstruction2.2 Other Documents:TMS 402/ACI 530/ASCE 5 Building Code Requirements for Masonry Structures3NBS Handbook 9143. Terminology3.1 Definitions:3.1.1 lot, nmaterial of a given quantity
18、 of a single type, grade, class, and brand and practically of the same nominal size, colorrange, texture, and composition produced by a single source by virtually the same process and under essentially the sameconditions.3.2 For additional terms used in this test method, refer to Terminology C1232.T
19、EST METHOD FOR LABORATORY-PREPARED SPECIMENS4. Summary of Test Method4.1 This test method is for evaluating the flexural bond strength (under the given conditions) of masonry built of standardmasonry units. It uses standard concrete masonry units. Mortars are batched by weight equivalents of volume
20、proportions and aremixed to a prescribed flow. Prisms are constructed using a jig and are bag-cured.NOTE 1Standard fired clay masonry units are under development but are not now available. When their development is complete, they will beincorporated into these test methods.5. Significance and Use5.1
21、 This test method is intended for use in comparing the bond strengths (under the given conditions) of masonry mortars.5.2 This test method could be used, for example, to check one aspect of the quality of mortar products after production, or toindicate the bond potential of a mortar product without
22、requiring the product to be tested in combination with many different units.5.3 This test method uses controlled conditions of fabrication and curing that are not intended to represent field conditions.5.4 This test method uses standard concrete masonry units. Mortars are batched by weight equivalen
23、ts of volume proportionsand are mixed to a prescribed flow. Prisms are constructed using a jig and are bag-cured.5.5 Flexural bond strength determined by this test method shall not be interpreted as the flexural bond strength of a wall(because standard units are not used for wall construction), nor
24、shall it be interpreted as an indication of extent of bond for purposesof water permeability evaluation.6. Apparatus6.1 Prism Alignment Jig, as described in Annex A2 and shown in Fig. A2.1.6.2 Mortar Joint Template, as described in Annex A2 and shown in Fig. A2.2.6.3 Drop Hammer, as described in Ann
25、ex A2 and shown in Fig. A2.3.6.4 Mechanical Paddle-Type Mortar Mixer, of no less than 0.6 ft3 (18 L) capacity.6.5 Flow Table, Flow Mold, and Caliper, conforming to the requirements of Specification C230/C230M.6.6 Cone Penetrometer, Unit Measure, Straightedge, Spatula, Tapping Stick, and Spoon, confo
26、rming to the requirements of TestMethod C780.6.7 Bond Strength Test Apparatus, conforming to the requirements of Annex A3.7. Materials7.1 Select representative samples of each lot of mortar materials. Each sample of material shall be of sufficient quantity to builda set of test prisms. Use standard
27、concrete masonry units meeting the requirements of Annex A1.7.2 Mortar materials (including water) shall be at an equilibrium temperature with laboratory air (see Section 8).3 Available from the Masonry Standards Joint Committee, http:/www.masonrystandards.org.4 Natrella, M. G.,Experimental Statisti
28、cs, National Bureau of Standards Handbook 91, U.S. Government Printing Office, Aug. 1, 1963, pp. 214.C1072 1328. Temperature and Humidity8.1 Maintain the temperature of laboratory air in the vicinity of mixing of mortar, fabrication of specimens, curing, and testingof specimens at 75 6 15F (24 6 8C)
29、.8.2 Maintain the relative humidity of laboratory air in the vicinity of mixing of mortar, fabrication of specimens, and testingof specimens between 30 and 80 %.9. Procedure9.1 Fabricate a set of stack-bonded test prisms (any convenient number of prisms) containing a total of not less than 15 mortar
30、joints. Each prism shall have no more than 5 joints.9.1.1 Proportion mortar materials by weights equivalent to volume proportions to be used in prism construction. Use unitweights for individual materials as given in Specification C270. Sand shall be permitted to be used in a damp loose condition,pr
31、ovided that moisture content of sand is determined with reference to the oven-dried condition and batch proportions are adjustedaccordingly. 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
32、below are measured from when water andcementitious materials are combined.9.1.2.1 For standard concrete masonry units, add an estimated amount of water to the mortar to achieve a flow of 127 6 3determined in accordance with Test Method C1437. Mix mortar for 3 min and determine flow. Once flow is rec
33、orded, return thematerial used to measure flow to the mixer. If the flow is 127 6 3, continue mixing the batch for an additional 2 min. If the flowis less than 124, add water to the batch, mix for 1 min, and determine flow. Once flow is recorded, return the material used tomeasure flow to the mixer.
34、 If the flow is 127 6 3, continue mixing the batch for 1 min.9.1.2.2 If after the one-time addition of water the flow is not 127 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 the mortar, determine its initial cone penetr
35、ation in accordance with Test Method C780.Determine the cone penetration of the mortar every 15 6 5 min. If the cone penetration is less than 80 % of its initial value, discardthe remaining portion of the mortar without constructing additional mortar joints.9.1.4 Use standard concrete masonry units
36、as defined in Annex A1. Clean the bed surface of units of dirt, loose sand, or othercontaminants.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 specimens.9.2.1 Test the prisms in the same facility
37、 where they were built.9.2.2 Test masonry prisms in accordance with Annex A3. Determine the flexural tensile strength of each mortar joint tested, asdescribed in Annex A3.NOTE 2When test ages other than 28 days are specified, the general relationship between the strength at the specified test age an
38、d that at 28 daysis generally established by test. That relationship may vary with different materials and curing conditions.10. Report10.1 Report the following information:10.1.1 Identify mortar materials and units tested, including as applicable the manufacturers name, brand name, type, grade,sour
39、ce 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 prisms perset of specimens and prism weight.10.1.3 Include the following in the report:10.1.3.1 Weight of ingredients (including water) added
40、to the batch of mortar.10.1.3.2 Flow or cone penetrometer reading of mortar used to construct prisms.10.1.3.3 Flexural bond strength test results for each joint of the test specimens. Mean, standard deviation, and test age for eachset of test specimens to the nearest psi.10.1.3.4 If one or more mort
41、ar joints break during the handling of the specimen and tightening of the loading clamps but beforeadditional load is applied by the testing apparatus, report which joints broke prematurely but do not include them in the calculationof the flexural tensile strength average and standard deviation. The
42、 top mortar joint shall be designated joint Number 1, the second,Number 2, etc. Measured loads and calculations shall also be included.10.1.3.5 Description of failure, especially indicating whether failure occurred at the top or bottom of the mortar joint, or both.C1072 13311. Precision and Bias11.1
43、 PrecisionPublished data are not available for within-laboratory variability of this test method. Published data(Hedstrom,5 Melander6) obtained under conditions almost identical with those of this test method show within-batch coefficientsof variation varying between 10 % and 25 % for 30-joint sampl
44、es of selected portland cement-lime mortars and masonry cementmortars. Because only one sample of each mortar was tested in each laboratory, sufficient data are not available to establishrepeatability for this test method. Inter-laboratory testing is now planned to determine the reproducibility of t
45、his test method. Itis the intent of this committee to develop precision values within five years from the date of issuance of this test method.11.2 BiasNo information can be presented on the bias of this test method because no test having an accepted reference valueis available.TEST METHOD FOR FIELD
46、-PREPARED SPECIMENS12. Summary of Test Method12.1 This test method is for evaluating the flexural bond strength (under the given conditions) of masonry built of conventionalmasonry units. Mortars are batched conventionally, and their flow is not prescribed. Prisms are constructed conventionally (no
47、jig)and are bag-cured.13. Significance and Use13.1 This test method is intended for evaluation of flexural bond strength (under the given conditions) between mortar and units.13.2 The purpose of this test method is to evaluate the bond strength (under the given conditions) of a particular unit-morta
48、rcombination, either for preconstruction evaluation of materials or for quality control purposes during construction. Preconstructionfield tests may be used to provide information on the potential performance of a mortar-unit combination under field conditionsof fabrication and workmanship (but not
49、curing). Construction field tests may be used as a quality control measure to ensure thatperformance criteria established in preconstruction tests are being met.13.3 Flexural bond strength determined by this test method shall not be interpreted as the flexural bond strength of a wallconstructed of the same material, nor shall it be interpreted as an indication of extent of bond for purposes of water permeabilityevaluation. However, if effects of construction conditions, specimen size, workmanship, and curing conditions are taken intoaccount, the results may be used t
