ASTM E518-2009 781 Standard Test Methods for Flexural Bond Strength of Masonry.pdf

1、Designation: E 518 09Standard Test Methods forFlexural Bond Strength of Masonry1This standard is issued under the fixed designation E 518; 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 paren

2、theses 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 cover determination of the flexuralbond strength

3、of unreinforced masonry assemblages. Twoprocedures are provided:1.1.1 Test Method ASimply supported beam with third-point loading.1.1.2 Test Method BSimply supported beam with uniformloading.1.2 The values stated in SI units are to be regarded as thestandard. The inch-pound units given in parenthese

4、s are forinformation only.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 pr

5、ior to use.2. Referenced Documents2.1 ASTM Standards:2C67 Test Methods for Sampling and Testing Brick andStructural Clay TileC78 Test Method for Flexural Strength of Concrete (UsingSimple Beam with Third-Point Loading)C 140 Test Methods for Sampling and Testing ConcreteMasonry Units and Related Unit

6、sC 270 Specification for Mortar for Unit MasonryC 778 Specification for Standard SandE4 Practices for Force Verification of Testing MachinesE72 Test Methods of Conducting Strength Tests of Panelsfor Building ConstructionE 575 Practice for Reporting Data from Structural Tests ofBuilding Constructions

7、, Elements, Connections, and As-semblies3. Significance and Use3.1 These test methods are intended to provide simplifiedand economical means for gathering comparative research dataon the flexural bond strength developed with different types ofmasonry units and mortar or for the purpose of checking j

8、obquality control (materials and workmanship).NOTE 1These test methods are not intended for use in establishingdesign stresses. For this purpose, Methods E72should be used.4. Apparatus4.1 Testing Machine, conforming to the requirements ofPractices E4.4.2 Test Method AThe third-point loading method i

9、sillustrated in Fig. 1. The minimum span between supports shallnot be less than 2.5 multiplied by the average depth of thespecimen. The distance between each support and the adjacentdistributed point load shall be one-third of the span length 63mm (0.1 in.). Steel rods with a maximum diameter of 25

10、mm(1 in.) shall be used to support the specimen and apply the load.The steel rods shall extend over the full width of the specimen.NOTE 2The loading apparatus is intended to be similar to that used inTest Method C78to reduce the need for redundant testing equipment.4.3 Test Method BThe uniform loadi

11、ng method is illus-trated in Fig. 2. The minimum span between supports shall notbe less than 2.5 multiplied by the average depth of thespecimen. Uniformly distributed transverse load shall be ap-plied by air pressure over the full surface of the specimen. Theair bag reaction frame shall fully contac

12、t one surface of the airbag and shall be sufficiently stiff as to not measurably deflectduring testing.NOTE 3Air bags manufactured using 0.5 mm (0.02 in.) thick polyvi-nyl chloride have been successfully used with this test. When testingspecimens constructed with a high bond-strength mortar, or whos

13、ethickness is greater than a nominal 100 mm (4 in.), the applied load1These 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 15, 2009. Published July 2009. Orig

14、inallyapproved in 1974. Last previous edition approved in 2003 as E 518 03.2For 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

15、 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.required to fail the specimen may be such as to rupture the seams of theair bag. In such cases Test Metho

16、d A is recommended.5. Sampling and Testing5.1 Masonry UnitsRepresentative masonry units shall besampled and tested in accordance with the following applicablemethods: Test Methods C67for brick, or Test Methods C 140for concrete masonry units. Minimum tests required shall becompressive strength, and

17、initial rate of absorption for brick orabsorption for concrete masonry units.5.2 MortarOne of the types of mortar in SpecificationC 270 shall be used, or the mortar shall conform to thatspecified for the construction. Sand sieve analysis shall beperformed and recorded, except when ASTM C 778 standar

18、dsand is used. If ASTM C 778 standard sand is used, the recordshall identify the sand as 2030 sand, graded sand, or a blendof indicated proportions of each sand by weight.5.2.1 Mortar for prism fabrication shall be mixed to aworkable consistency. The compressive strength, initial flow,and water rete

19、ntion of the mortar shall be determined inaccordance with the requirements of Specification C 270,except that the cubes molded for the compressive strength test,after moist curing in the molds for 24 h, shall be released andstored in the same atmosphere as the prisms as specified inSection 7. The fo

20、llowing physical properties of the mortar shallbe determined and recorded:5.2.2 Compressive strength (average of three cubes),5.2.3 Initial flow (laboratory-mixed mortar only),5.2.4 Flow after suction (water retention) (laboratory-mixedmortar only).6. Test Specimens6.1 A minimum of five test specime

21、ns shall be constructedas stack-bonded prisms, at least 460 mm (18 in.) high withmortar joints 10 6 1.5 mm (38 6116 in.) in thickness. Thenumber of courses in each specimen shall be such as to permitlocating supports and loading points midway between joints forFIG. 1 The Third-Point Loading Method (

22、Test Method A)FIG. 2 The Uniform Loading Method (Test Method B)E518092Test Method A tests (4, 7, 10, 13, or 16 courses, depending onface heights of units), and to provide for a span-to-depth ratiothat exceeds 2.5. When the test is for the purpose of determin-ing the quality of materials and workmans

23、hip during construc-tion, the specimens shall be constructed at the site by themasons involved, utilizing the materials on the site and thesame masonry construction techniques.6.2 Applicable portions of the following procedures shall beobserved:6.2.1 Set units on a firm, flat surface without the use

24、 ofmortar, leaving not less than 50-mm (2-in.) spaces betweenstretchers.6.2.2 Place a full or face shell mortar bed (in accordancewith job specification) on all units without furrowing.6.2.3 Immediately place the next course of units on themortar bed and tap each unit to level.Align at least one ver

25、ticalface of each prism to a plane using a level or other means.(Note 4).6.2.4 Repeat steps 6.2.2 and 6.2.3 until the prisms are therequired number of courses high. Tool or otherwise finish thejoints as specified.NOTE 4A convenient method of aligning one face is to use a jig asillustrated in Fig. 3.

26、7. Handling and Curing Conditions7.1 Unless otherwise specified, all prisms shall be cured for28 days. The prisms together with corresponding mortar cubesshall be cured in laboratory air maintained at a temperature of24 6 8C (75 6 15F), with a relative humidity between 30and 70 %, and free of drafts

27、. These environmental conditionsgenerally will not require special air-conditioning equipment.A continuous graphical record of temperature and humiditywill suffice to detect unusual dryness or excessive moisture,together with unusual fluctuations of temperature.7.1.1 Where prisms are made during con

28、struction at the jobsite, they shall be constructed in a place where they will not bedisturbed, but will be subjected to air conditions similar tothose in the masonry structure.8. Procedure8.1 Place the test specimen horizontally on its supports as asimply supported beam. If full contact is not obta

29、ined betweenthe specimen and the load-applying blocks and supports,compressible shims or a bed of gypsum capping material shallbe used to level and seat the specimen thereby ensuring theuniform application of load. If compressible shims are used,they shall be made of leather or similar compressible

30、materialFIG. 3 Use of a Jig to Align One Face of a Prism to a PlaneE518093of uniform-thickness, not less than 6 mm (14 in.) thick, 25 to 50mm (1 to 2 in.) in width, and shall extend across the full widthof the specimen.8.2 Apply the load at a uniform rate of travel of the movinghead such that the to

31、tal load is applied in not less than 1 normore than 3 min.8.3 Record the maximum applied load in Newtons (pounds)as P and the location of the break.9. Calculation9.1 For specimens built with solid masonry units (75 % ormore net area), calculate the gross area modulus of rupture asfollows (See Note 5

32、):9.1.1 For Test Method A, with third-point loading:R 5P 1 0.75 Ps!lbd2(1)where:R = gross area modulus of rupture, MPa (or psi),P = maximum applied load indicated by the testingmachine, N (or lbf),Ps= weight of specimen, N (or lbf),l = span, mm (or in.),b = average width of specimen, mm (or in.), an

33、dd = average depth of specimen, mm (or in.).9.1.2 For Test Method B, with uniform loading:R 50.75 P 1 Ps!lbd2(2)where the terms are the same as those described in 9.1.1.9.2 For specimens built with hollow masonry units (lessthan 75 % net area), calculate the net area modulus of ruptureas follows (Se

34、e Note 5):9.2.1 For Test Method A, with third-point loading:R 50.167 P 1 0.125 Ps!lS(3)where:S = section modulus of actual net bedded area, mm3(orin.3).9.2.2 For Test Method B, with uniform loading:R 50.125 P 1 Ps!lS(4)where S is the same as in 9.2.1.NOTE 5The equations for determining the modulus o

35、f rupture valuesin 9.1 and 9.2 assume that the location of the failure plane occurs at themid-span of the specimen. Where the failure location is other thanmid-span, the use of these equations for determining the modulus ofrupture will not be entirely accurate. Where a more precise assessment ofthe

36、specimens modulus of rupture values is deemed appropriate, a morethorough analysis using accepted engineering mechanics should beemployed.9.3 If the failure occurs in a joint outside of the middle thirdof the span length for Method A, discard the test results.10. Report10.1 The report shall be prepa

37、red in conformance withPractice E 575 and shall include the following:10.1.1 Identification number,10.1.2 Average width of specimen to the nearest 1.0 mm(0.05 in.),10.1.3 Average depth of specimen to the nearest 1.0 mm(0.05 in.),10.1.4 Weight of specimen, N (or lbf),10.1.5 Method of applying load (M

38、ethod A or B),10.1.6 Maximum applied load, N (or lbf),10.1.7 Individual and average gross or net area moduli ofrupture calculated to the nearest MPa (or psi); standarddeviation; and coefficient of variation.10.1.8 Curing history and age of specimen,10.1.9 Defects in specimen,10.1.10 Description of f

39、ailure,10.1.11 Type and mix design of mortar,10.1.12 Compressive strength of mortar, kPa (or psi),10.1.13 Initial flow of mortar as used (laboratory-mixedmortar only),10.1.14 Water retention of mortar (laboratory-mixed mortaronly),10.1.15 Physical properties of masonry units, and10.1.16 Sketch or ph

40、otograph of masonry unit showing coreconfiguration and mortar bedded area, full or face shell.10.1.17 Results of the sand sieve analysis or, if ASTMC 778 sand is used, identify which of the defined sands wereused.11. Precision and Bias11.1 No statement is made either on the precision or on thebias o

41、f these test methods due to the variety of materials andcombinations of materials involved. Sufficient test data for allmaterials and combinations of materials are not presentlyavailable to permit the development of precision and biasstatements.12. Keywords12.1 flexural bond strength; masonry units;

42、 mortar; simplysupported beam; stack bonded prism; third point loading;uniform loadE518094SUMMARY OF CHANGESCommittee C15 has identified the location of selected changes to this standard since the last issue (E 518 03)that may impact the use of this standard. (Approved June 15, 2009.)(1) Subsection

43、4.2 was modified to improve clarity.(2) Subsection 4.3 was modified to improve clarity.(3) Note 5 was added to clarify the assumptions and limita-tions inherent in equations.(4) Subsection 10.1.16 was modified to allow the use ofphotographs as an alternative to sketches.ASTM International takes no p

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