ASTM C1197-2014a Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method《采用液压千斤顶法现场测量砖石工程可变形性能的标准试验方法》.pdf

《ASTM C1197-2014a Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method《采用液压千斤顶法现场测量砖石工程可变形性能的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM C1197-2014a Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method《采用液压千斤顶法现场测量砖石工程可变形性能的标准试验方法》.pdf（6页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C1197 14aStandard Test Method forIn Situ Measurement of Masonry Deformability PropertiesUsing the Flatjack Method1This standard is issued under the fixed designation C1197; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisio

2、n, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method describes an in situ method fordetermining the deformation properties of existing unr

3、ein-forced solid-unit masonry. (See Note 1.) This test methodconcerns the measurement of in-situ masonry deformabilityproperties in existing masonry by use of thin, bladder-likeflatjack devices that are installed in cut mortar joints in themasonry wall. This test method provides a relatively non-des

4、tructive means of determining masonry properties.NOTE 1Solid-unit masonry is that built with stone, concrete, or clayunits whose net area is equal to or greater than 75 % of the gross area.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are ma

5、thematicalconversions 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 theresponsibility of the user of this standard to establish appro-priate safety and

6、health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C1180 Terminology of Mortar and Grout for Unit MasonryC1232 Terminology of MasonryE74 Practice of Calibration of Force-Measuring Instrumentsfor Verifying the Force Indi

7、cation of Testing Machines3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 shim, nitem inserted into a flatjack slot prior totesting to minimize the inflation of the test flatjack.3.1.1.1 DiscussionThe use of shims may be necessaryduring testing to achieve a tight fit of the fl

8、atjack in the slot andto ensure uniform transfer of pressure (stress) to the masonryover the complete area of the flatjack. SeeAnnexA1 for furtherdiscussion on allowable types of shims.3.1.2 spacer, nmetal plate used in the calibration processto control flatjack thickness.3.2 For definitions of othe

9、r terms used in this test methodrefer to Terminology C1180 for mortar and grout and Termi-nology C1232 for masonry.4. Summary of Test Method4.1 Two flatjacks inserted into parallel slots, one above theother, in a solid-unit masonry wall are pressurized thusinducing compressive stress on the masonry

10、between them.The installation is shown in Fig. 1. By gradually increasing theflatjack pressure and measuring the deformation of the ma-sonry between the flatjacks, load-deformation (stress-strain)properties may be obtained. Maximum compressive strengthsmay be measured in certain cases.5. Significanc

11、e and Use5.1 Deformation and strength properties are measured onlyon the masonry between flatjacks. Boundary effects of thecollar joint behind the wythe tested and adjacent masonry areneglected. In the case of multi-wythe masonry, deformability isestimated only in the wythe in which the flatjack is

12、inserted.Deformability of other wythes may be different.6. Apparatus6.1 Flatjack:6.1.1 Aflatjack is a thin envelope-like bladder with inlet andoutlet ports which may be pressurized with hydraulic fluid.Flatjacks may be of any shape in plan, and are designed to becompatible with the masonry being tes

13、ted. For determiningload-deformation properties of masonry, flatjacks are typicallyrectangular or semi-rectangular as shown in Fig. 2.6.1.2 For determination of the state of compressive stress,dimension A should be equal to or greater than the length of asingle masonry unit, but not less than 8 in.

14、(200 mm).Dimension B should be equal to or greater than the thicknessof one wythe and not less than 3 in. (75 mm). The radius, R, for1This test method is under the jurisdiction of ASTM Committee C15 onManufactured Masonry Units and is the direct responsibility of SubcommitteeC15.04 on Research.Curre

15、nt edition approved Dec. 1, 2014. Published December 2014. Originallyapproved in 1992. Last previous edition approved in 2014 as C1197 14. DOI:10.1520/C1197-14A.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book o

16、f ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.*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 States1circular and semi-rec

17、tangular flatjacks shall be equal to theradius of the circular saw blade used to cut the slot.6.1.3 Flatjacks shall be made of metal or other material suchthat the flatjack in a slot in masonry will be capable of applyingoperating pressures up to the expected maximum flatjackpressure. See Note 2. Me

18、tal flatjacks suitable for this purposeshall be made of type 304 stainless steel sheet of 0.024(0.6 mm) to 0.048 in. (1.2 mm) in thickness with welded seamsalong the edges, and incorporating hydraulic inlet or outletports.NOTE 2A maximum operating pressure of 1000 psi (6.9 MPa) isadequate for older

19、existing masonry, but flatjacks with higher operatingpressures may be required for more recently constructed buildings.Flatjacks manufactured with flexible polymers that have operating pres-sure ranges of less than 1000 psi (6.9 MPa) may be useful for stressmeasurements in some historic masonry.6.1.

20、4 Calibrate all flatjacks as described in Section 8 todetermine their pressure-applied load characteristics.6.2 Hydraulic SystemA hydraulic pump with hydraulichoses is required. Hose connections shall fit the flatjack inletport. Measure pressure using gauges calibrated to a traceablestandard having

21、both an accuracy of 1 % of full hydraulic scaleand an appropriate operating range. The hydraulic system shallbe capable of maintaining constant pressure within 1 % of fullscale for at least 5 min.6.3 Displacement MeasurementMeasure displacements ofthe masonry with electronic instrumentation, for exa

22、mple, aLinearly Variable Differential Transformer (LVDT) mounted tothe surface of the masonry between the flatjacks, or by amechanical gauge extensometer which measures the distancebetween fixed gauge points on the masonry as shown in Fig. 1.The method or device used to measure deformations shall be

23、capable of deformation measurements up to316 in. (5 mm).Deformation measurements shall have an accuracy of at least60.005 % of gauge length. Record measurements manually atdiscrete intervals, or continuously by automatic data recording.6.4 Attachment of Measurement DevicesAttach bracketsfor mounting

24、 electrical displacement measuring devices orgauge points to be used with mechanical devices securely tothe surface of the masonry to prevent movement and ensure therequired measurement accuracy. Use rigid adhesive for discsand brackets and cementitious grout for plugs. If gauge pointsare used, the

25、gauge points shall have a conical depression attheir center, compatible with the pointed elements of theextensometer. The angles of the depression of the cone and theextensometer points shall be the same.7. Preparation of Slots7.1 Slots in masonry are normally prepared by removing themortar from mas

26、onry bed joints to avoid disfiguring themasonry. Remove all mortar in the bed joint, that is, pressureexerted by a flatjack shall be directly against the surfaces of themasonry units.7.2 The plan geometry of the slot shall be similar to that ofthe flatjack being used. Plan dimensions of the prepared

27、 slotshall not exceed those of the flatjack by more than12 in.(12 mm). Slots shall be parallel and aligned vertically, andshall be separated by not more than 1.5 times the length of theflatjack.7.3 Prepare rectangular slots into which rectangular flat-jacks are to be inserted by drilling adjacent or

28、 overlappingholes (stitch drilling) and subsequently using a drill, bar, or toolto remove mortar and produce a slot of desired dimensionswith smooth upper and lower surfaces. Other tools, such asoscillating blade grinders, that can be reliably used to formrectangular slots in masonry mortar joints w

29、ithout damagingthe surrounding masonry are also permitted to be used.7.4 Prepare slots for circular and semi-rectangular flatjacksusing circular saws of sufficient radius to provide the depthrequired (Fig. 2, dimension B). Use carbide or diamond tippedblades to remove all mortar from the slot.8. Cal

30、ibration8.1 A flatjack has an inherent stiffness which resists expan-sion when the jack is pressurized. Therefore, the fluid pressurein the flatjack is greater than the stress the flatjack applies tomasonry. A flatjack must be calibrated to provide a conversionfactor, Km, to relate internal fluid pr

31、essure to applied stress.8.2 Calibrate flatjacks in a compression machine of at least100 kip (450 KN) capacity which has been calibrated accord-ing to Practice E74.8.3 Place a 2 in. (50 mm) thick steel bearing plate on thelower platen of the compression machine. The bearing plateshall be of sufficie

32、nt size to completely cover the flatjack beingcalibrated. Place the flatjack on the lower bearing plate suchthat the edge of the flatjack with the inlet/outlet ports iscoincident with the edge of the bearing plate. Place steelFIG. 1 Deformation Properties Using Two FlatjacksFIG. 2 Flatjack Configura

33、tions (Plan View)C1197 14a2spacers around the other edges of the flatjack. The thickness ofthe spacers shall be 0.015 to 0.050 in. (0.38 to 1.27 mm)greater than the sum of the combined thickness of the twosheets plus the thickness of inlet/outlet port used in fabricationof the flatjack. Place the up

34、per 2 in. (50 mm) thick bearingplate on top of the spacers and flatjack, and align it to bedirectly above the lower bearing plate. Position the bearingplate/flatjack/spacer assembly on the lower platen such that thecentroid of the area of the flatjack is within14 in. (6 mm) of theaxis of thrust of t

35、he test machine. The calibration setup isillustrated in Fig. 3.8.4 Raise or lower the moveable platen such that bothplatens are in contact with the bearing plates. Apply a pre-loadsufficient to provide full contact between the bearing plates andthe spacers, equivalent to 10 psi (0.07 MPa) over the g

36、ross areaof the flatjack.8.5 The distance between platens must be held constantduring the calibration procedure. Fix the displacement of thetest machine at this point if using a displacement-controlmachine. If not, attach displacement gauges (mechanical orelectrical) such that the distance between p

37、latens established bythe procedures of paragraph 8.4 can be held constant whenusing a force-control test machine.8.6 Pressurize and depressurize the flatjack three times overthe full operating pressure range. Do not exceed the maximumflatjack operating pressure.8.6.1 While holding the distance betwe

38、en the platensconstant, increase the pressure in the flatjack in equal incre-ments to within 5 percent of the maximum flatjack operatingpressure. Use at least 10 equal increments between 0 psi andthe maximum flatjack operating pressure. At each increment,record flatjack hydraulic pressure and force

39、applied by the testmachine.8.7 Calculate the load applied by the flatjack as internalpressure times gross flatjack area. Plot flatjack load versus loadmeasured by the test machine with the flatjack load on thehorizontal axis of the plot. The slope of the line equals theflatjack constant, that is, th

40、e conversion factor:Km5 PmachinePflatjack(1)8.8 Recalibrate flatjacks after using five times or whendistortion appears excessive.9. Procedure9.1 The location where masonry deformability estimates areconducted is dictated by engineering objectives. The basicarrangement is illustrated in Fig. 1. At th

41、e desired location orlocations the following steps should be taken.9.2 Select and mark a visible line on the masonry to definethe location and length of slots to be formed.9.3 Prepare the slots (see Note 3) (see Section 7) and recordthe measured slot dimensions. Clean slots of all mortar andbrick pa

42、rticles prior to the insertion of flatjacks. Slots shall beseparated by at least five courses of masonry, but not more than1.5 times the length of the flatjack.NOTE 3The location of the slots shall be at least 112 flatjack lengthsfrom wall openings or ends. There should be sufficient masonry above t

43、hetop slot to resist forces developed during pressurization of the flatjacks.9.4 Attach at least three equally spaced pairs of gauge pointsor electrical measuring devices as shown in Fig. 1. Centermeasurement points vertically between flatjacks, with a mini-mum gauge length of 8 in. Locate the measu

44、rement points onmasonry units, not at mortar joints. The first and last measure-ment points should be located at least a distance A/8 in from theends of the slot, where A is the flatjack length as shown in Fig.2.FIG. 3 Flatjack Calibration Setup (Elevation View)C1197 14a39.5 Insert the flatjack into

45、 the slot. Shim, as required, toachieve a tight fit and bridge over any interior voids in themasonry. See Annex A1 for a description of flatjack shims andtheir use.9.6 Connect hydraulic hoses and fill the flatjacks withhydraulic fluid until pressure begins to develop.9.7 In order to seat the flatjac

46、k and any shims, pressurize theflatjack to approximately 50 % of the estimated maximumflatjack pressure (which corresponds to the estimated maxi-mum compressive strength of the masonry). Reduce theflatjack pressure to zero.9.8 Take initial measurements with mechanical devices(three repetitions) or i

47、nitialize electrical devices.9.9 Increase pressure slowly. Take displacement measure-ments at small increments of pressure. If measurements are tobe taken manually, stop and hold the pressure for at least oneminute or until pressure is steady at each incremental step, andrecord displacements (three

48、repetitions at each gauge point inthe case of mechanical measurement devices). Monitor theflatjack pressure-masonry deformation ratio, p, during the testat each increment of pressure. If failure of the masonrybetween flatjacks is not desired, the test should stop when theabove ratio begins to notice

49、ably decrease.9.10 In older masonry or masonry of low-strength units andlow or zero cement content mortar, flatjacks are capable ofloading the masonry between them to failure thus establishingmaximum strength. However, this may also cause damage tothe masonry in areas adjacent to the flatjacks.9.11 Release pressure after the final displacement measure-ment has been taken.9.12 Disconnect hoses and remove the flatjack. The slotmay be filled with mortar or other suitable material of a colorand strength similar to the original mortar.10. Calculation10.1 Calculate stress