ASTM C1006-2007 Standard Test Method for Splitting Tensile Strength of Masonry Units《砌块的拉裂强度的标准试验方法》.pdf

1、Designation: C 1006 07Standard Test Method forSplitting Tensile Strength of Masonry Units1This standard is issued under the fixed designation C 1006; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb

2、er in 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 the determination of the split-ting tensile strength of masonry units.1.2 The values stated in inch-pound units a

3、re to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand 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 theresponsibilit

4、y 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:2E4 Practices for Force Verification of Testing Machines3. Significance and Use3.1 Masonry units alon

5、e and within assemblages commonlyfail in a tensile mode when loaded in compression to failure.These tensile stresses result from differences in modulus ofelasticity and Poissons ratio between the masonry unit andmortar. Additionally, the dissimilarity in behavior of the groutwithin cores of masonry

6、units under load leads to tensilestresses in the units and results in a splitting failure.3.2 This test method produces a line load along the bedsurface of the masonry unit. The compressive load applied tothe unit, imposed by means of bearing rods, results in a tensilestress distributed over the hei

7、ght of the unit for the split lengthof the unit. This test method can be conducted with the rodoriented either in the longitudinal direction or in the transversedirection of the bed face. The splitting tensile strength iscalculated by the equation given in 7.1.3.3 The test value provides an indicato

8、r of masonry-unitsplitting tensile strength. Additionally, the presence of defectssuch as visible voids or impurities in masonry units may berevealed.4. Apparatus4.1 Bearing RodsMatched, paired steel bearing rods withdiameters within18 to112 of the specimen height, of a lengthgreater than the length

9、 of the intended test area, and ofstraightness within 0.5 % of the specimen length shall beprovided for each unit. Bearing rods that meet the straightnessrequirement can be reused.4.2 Supplemental Bearing Bar or PlateIf the diameter orlargest dimension of the upper bearing face or lower bearingblock

10、 is less than the length of the specimen to be tested, asupplementary bearing bar or plate shall be used. The contactsurfaces of the bar or plate shall be machined to within 0.05 %of planeness as measured on any line of contact of the bearingarea. The bearing bar or plate shall have a width of at le

11、ast 2in. (51 mm), and a thickness not less than the distance from theedge of the spherical or rectangular bearing block to the end ofthe specimen. The bar or plate shall be used in such a mannerthat the load will be uniformly applied over the entire intendedsplit length of the specimen.4.3 Testing M

12、achine:4.3.1 The testing machine shall conform to the requirementsof Practices E4, and may be of any type of sufficient capacitythat will provide the rate of loading prescribed in 6.3.4.3.2 The upper, hardened metal bearing face shall bespherically seated and attached at the center of the upper head

13、of the machine. The center of the sphere shall lie at the centerof the surface of the plate in contact with the specimen. Thebearing plate shall be closely held in its spherical seat but shallbe free to turn in any direction; its perimeter at the ball faceshall have at least14 in. (6.4 mm) clearance

14、 from the head ofthe machine to allow for specimens whose test surfaces are notexactly parallel. The diameter of the bearing surface shall be atleast 5 in. (127 mm). The bearing block surfaces that will1This test method is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and

15、 is the direct responsibility of SubcommitteeC15.04 on Research.Current edition approved Oct. 1, 2007. Published October 2007. Originallyapproved in 1984. Last previous edition approved in 2001 as C 1006 84 (2001).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM C

16、ustomer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer 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 Conshohoc

17、ken, PA 19428-2959, United States.contact the bearing bar or plate shall not depart from planesurfaces by more than 0.05 %.5. Sampling5.1 SelectionFor the purpose of this test, full-size ma-sonry units shall be selected at random by the purchaser or byhis authorized representative. The specimens sha

18、ll be represen-tative of the whole lot of units from which they are selected andshall include units representative of the complete range ofcolors and sizes in the shipment.5.2 NumberA minimum of five specimens shall be testedfor the first 250 000 units. The minimum number of testspecimens shall be i

19、ncreased by one unit for each 50 000additional units or fraction thereof.6. Procedure6.1 Positioning Bearing Rods:6.1.1 For units less than 4 in. (102 mm) high, mark theintended location of the split surface on both faces, stretcher ornormally exposed faces for transverse splitting, and end facesfor

20、 longitudinal splitting. Spread a gypsum capping compound(Note 1) along the bed surface between these two marks. Placethe bearing rod into the fresh compound and press until contactis made with the unit. After the compound has set, place thesecond bearing rod parallel to the first on the opposite be

21、dsurface using an alignment device as illustrated in Fig. 1. Thetwo rods must be within14 in. (6.4 mm) in 8 in. (203 mm) ofbeing parallel.NOTE 1The gypsum capping compound shall be an alphagypsumhydrate hemihydrate, such as U.S. Gypsum Hydrostone.6.1.2 For units $4 in. (102 mm) high, use a carpenter

22、ssquare to draw a line perpendicular to the bed surface onopposite exterior faces. Spread capping compound on theupper bed surfaces between the two lines. Align the bearingrods with the lines on the faces, and press one rod into the freshcompound until in contact with the unit. After the compoundhas

23、 set, invert the unit and repeat this procedure on the oppositebed surface. The two companion rods must be within14 in. (6.4mm) in 8 in. (203 mm) of being parallel.6.1.3 The bearing rods shall be positioned no closer to a freeedge than one half the specimen height.6.1.4 Cure the capping compound for

24、 at least2hat75615F (24 6 8C) prior to testing.NOTE 2Alternative methods of applying the line load to the specimenhave been used. Wood strips, metal bars of square cross section, and halfrounds have been utilized. Such devices, meeting the dimensionalrequirements of 4.1, are permitted on specimens g

25、reater than 4 in. (102mm) in height. The user of any modification should provide comparativedata, testing both ways, to validate the alternative method.6.2 Test AlignmentAlign the rods with the centerline ofthe plates, and center the rods in the transverse direction.Support the specimen on compressi

26、ble rods or tubes that are116 in. (1.6 mm) smaller in diameter than the bearing rods.Remove the compressible rods when the specimen is held invertical orientation by the testing-machine platens.6.3 Rate of LoadingApply the load without impact andload continuously at a rate less than 2000 lbf/min (89

27、00N/min).NOTE 3This requirement is met if the speed of the moving head of thetesting machine immediately prior to application of load is not more than0.5 in./min (12.7 mm/min).6.4 MeasurementDetermine the height of the specimen tothe nearest 0.1 in. (2.5 mm) by averaging three heightsmeasured near t

28、he ends and the middle and on a planeperpendicular to the bed surface. Determine the split length ofthe specimen to the nearest 0.1 in. (2.5 mm) by averaging atleast two measurements taken on the plane of the bearing rods.The split length is the actual net length of the failure plane ofthe bearing r

29、ods and is equal to the gross length of the unitminus the length of any voids along this plane.7. Calculations7.1 Calculate the splitting tensile strength of the specimensas follows:ft5 2P/pLH (1)where:ft= splitting tensile strength, psi (kPa),P = maximum applied load indicated by the testing ma-chi

30、ne, lb (kN),L = split length, in. (mm), gross length minus the length ofany voids along the failure plane of the bearing rods,andH = distance between rods, in. (mm).8. Report8.1 The report shall include the following for each masonryunit.8.1.1 Type and dimensions of specimen,8.1.2 Identification num

31、ber,8.1.3 Split length and height of split area of specimen ininches (mm),8.1.4 Maximum load in pound force (kilonewtons),8.1.5 Splitting tensile strength calculated to the nearest 5 psi(50 kPa),FIG. 1 Example of Alignment Jig for Maintaining Parallel BearingRodsC 1006 0728.1.6 Visible voids and imp

32、urities in specimen, and8.1.7 Description of fracture.8.2 Report and average splitting tensile strength of the unitstested.9. Precision and Bias9.1 The laboratory coefficient of variation of test resultsavailable is high because of the variability of the materialproperty tested. Coefficients of vari

33、ation for groups of fivespecimens ranged from 3 to 40 %, averaging 20 %.9.1.1 It is expected that the multilaboratory coefficients ofvariation will be higher than the single operator or singlelaboratory coefficient of variation.9.1.2 Tests conducted with rods oriented longitudinally onbed faces norm

34、ally have higher coefficients of variation thantests conducted with rods oriented transversely.10. Keywords10.1 brick; concrete masonry units; masonry; splittingstrength; tensile strengthSUMMARY OF CHANGESCommittee C15 has identified the location of selected changes to this standard since the last i

35、ssue (C 1006 84(2001) that may impact the use of this standard. (Approved Oct. 1, 2007.)(1) Subsections 3.2 and 9.1.2 have been modified to clarify themeaning of testing in the longitudinal and transverse direc-tions.(2) Changes have been made throughout the standard to adjustthe metric equivalences

36、 so that they have the same number ofsignificant figures as the inch-pound units.(3) The curing temperature range in 6.1.4 has been changed tomake it consistent with other laboratory test methods.(4) Note 1 has been modified to remove a reference to amaterial source that is not commonly used.(5) Sub

37、section 6.4 and the definition for L in 7.1 have beenmodified to clarify how to determine the split length.(6) Eq 1 has been modified to change T to the more commonlyused ft.(7) The definition for H in 7.1 has been clarified.(8) Fig. 1 has been clarified by showing the orientation of Land H.ASTM Int

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40、ould be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on St

41、andards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).C 1006 073