ASTM C1197-2014 Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method《用液压千斤顶法现场测量砖石建筑可变形性的标准试验方法》.pdf

《ASTM C1197-2014 Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method《用液压千斤顶法现场测量砖石建筑可变形性的标准试验方法》.pdf》由会员分享，可在线阅读，更多相关《ASTM C1197-2014 Standard Test Method for In Situ Measurement of Masonry Deformability Properties Using the Flatjack Method《用液压千斤顶法现场测量砖石建筑可变形性的标准试验方法》.pdf（7页珍藏版）》请在麦多课文档分享上搜索。

1、Designation: C1197 09C1197 14Standard 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

2、revision, 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 for determining the deformation properties of exis

3、ting unreinforced solid-unitmasonry. (See Note 1.)This test method concerns the measurement of in-situ masonry deformability properties in existing masonryby use of thin, bladder-like flatjack devices that are installed in saw cut mortar joints in the masonry wall.This test method providesa relative

4、ly non-destructive means of determining masonry properties.NOTE 1Solid-unit masonry is that built with stone, concrete, or clay units 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 regarded as standard. The values given in parent

5、heses are mathematicalconversions to SI units that are provided for 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 appropriat

6、e safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E74 Practice of Calibration of Force-Measuring Instruments for Verifying the Force Indication of Testing Machines3. Summary of Test Method3.1 Two flatjacks i

7、nserted into parallel slots, one above the other, in a solid-unit masonry wall are pressurized thus inducingcompressive stress on the masonry between them. The installation is shown in Fig. 1. By gradually increasing the flatjack pressureand measuring the deformation of the masonry between the flatj

8、acks, load-deformation (stress-strain) properties may be obtained.Maximum compressive strengths may be measured in certain cases.4. Significance and Use4.1 Deformation and strength properties are measured only on the masonry between flatjacks. Boundary effects of the collarjoint behind the wythe tes

9、ted and adjacent masonry are neglected. In the case of multi-wythe masonry, deformability is estimatedonly in the wythe in which the flatjack is inserted. Deformability of other wythes may be different.5. Apparatus5.1 Flatjack:5.1.1 A flatjack is a thin envelope-like bladder with inlet and outlet po

10、rts which may be pressurized with hydraulic oil.fluid.Flatjacks may be of any shape in plan, and are designed to be compatible with the masonry being tested. For determiningload-deformation properties of masonry, flatjacks are typically rectangular or semi-rectangular as shown in Fig. 2.5.1.2 For de

11、termination of the state of compressive stress, dimension A should be equal to or greater than the length of a singlemasonry unit, but not less than 8 in. (200 mm). Dimension B should be equal to or greater than the thickness of one wythe andnot less than 3 in. (75 mm). The radius, R, for circular a

12、nd semi-rectangular flatjacks shall be equal to the radius of the circularsaw blade used to cut the slot.1 This test method is under the jurisdiction ofASTM Committee C15 on Manufactured Masonry Units and is the direct responsibility of Subcommittee C15.04 on Research.Current edition approved June 1

13、, 2009July 1, 2014. Published July 2009August 2014. Originally approved in 1992. Last previous edition approved in 20042009 asC1197 04.C1197 09. DOI: 10.1520/C1197-09.10.1520/C1197-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.

14、org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM 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. Becausei

15、t may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In 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 a

16、t the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.1.3 Flatjacks shall be made of metal or other material such that the flatjack in a slot in masonry will be capable of applyingoperating pressures up to the ex

17、pected maximum flatjack pressure. See Note 2. Metal flatjacks suitable for this purpose shall bemade of type 304 stainless steel sheet of 0.024 (0.6 mm) (0.6 mm) to 0.048 in. (1.2 mm) in thickness with welded seams alongthe edges, and incorporating hydraulic inlet or outlet ports.NOTE 2A maximum ope

18、rating pressure of 1000 psi (6.9 MPa) is adequate for older existing masonry, but flatjacks with higher operating pressuresmay be required for more recently constructed buildings. Flatjacks manufactured with flexible polymers that have operating pressure ranges of less than1000 psi (6.9 MPa) may be

19、useful for stress measurements in some historic masonry.5.1.4 Calibrate all flatjacks as described in Section 7 to determine their pressure-applied load characteristics.5.2 Hydraulic SystemA hydraulic pump with hydraulic hoses is required. Hose connections shall fit the flatjack inlet port.Measure p

20、ressure using gauges calibrated to a traceable standard having both an accuracy of 1 % of full hydraulic scale and anappropriate operating range. The hydraulic system shall be capable of maintaining constant pressure within 1 % of full scale forat least 5 min.5.3 Displacement MeasurementMeasure disp

21、lacements of the masonry with electronic instrumentation, for example, aLinearly Variable Differential Transformer (LVDT) mounted to the surface of the masonry between the flatjacks, or by amechanical gauge extensometer which measures the distance between fixed gauge points on the masonry as shown i

22、n Fig. 1. Themethod or device used to measure deformations shall be capable of deformation measurements up to 316 in. (5 mm). Deformationmeasurements shall have an accuracy of at least 60.005 % of gauge length. Record measurements manually at discrete intervals,or continuously by automatic data reco

23、rding.5.4 Attachment of Measurement Devices DevicesAttach brackets for mounting electrical displacement measuring devicesor gauge points to be used with mechanical devices securely to the surface of the masonry to prevent movement and ensure therequired measurement accuracy. Use rigid adhesive for d

24、iscs and brackets and cementitious grout for plugs. If gauge points areused, the gauge points shall have a conical depression at their center, compatible with the pointed elements of the extensometer.The angles of the depression of the cone and the extensometer points shall be the same.6. Preparatio

25、n of Slots6.1 Slots in masonry are normally prepared by removing the mortar from masonry bed joints to avoid disfiguring the masonry.Remove all mortar in the bed joint, that is, pressure exerted by a flatjack shall be directly against the surfaces of the masonry units.6.2 The plan geometry of the sl

26、ot shall be similar to that of the flatjack being used. Plan dimensions of the prepared slot shallnot exceed those of the flatjack by more than 12 in. (12 mm). (12 mm). Slots shall be parallel and aligned vertically, and shall beseparated by not more than 1.5 times the length of the flatjack.FIG. 1

27、Deformation Properties Using Two FlatjacksFIG. 2 Flatjack Flatjack Configurations (Plan View)C1197 1426.3 Prepare rectangular slots into which rectangular flatjacks are to be inserted by drilling adjacent or overlapping holes (stitchdrilling) and subsequently using a drill, bar, or tool to remove mo

28、rtar and produce a slot of desired dimensions with smooth upperand lower surfaces. Other tools, such as oscillating blade grinders, that can be reliably used to form rectangular slots in masonrymortar joints without damaging the surrounding masonry are also permitted to be used.6.4 Prepare slots for

29、 circular and semi-rectangular flatjacks using circular saws of sufficient radius to provide the depth required(Fig. 2, dimension B). Use carbide or diamond tipped blades to remove all mortar from the slot.7. Calibration7.1 Aflatjack has an inherent stiffness which resists expansion when the jack is

30、 pressurized. Therefore, the fluid pressure in theflatjack is greater than the stress the flatjack applies to masonry. A flatjack must be calibrated to provide a conversion factor, Km,to relate internal fluid pressure to applied stress.7.2 Calibrate flatjacks in a compression machine of at least 100

31、 kip (450 KN) capacity which has been calibrated according toPractice E74.7.3 Place a 2 in. (50 mm) thick steel bearing plate on the lower platen of the compression machine. The bearing plate shall beof sufficient size to completely cover the flatjack being calibrated. Place the flatjack on the lowe

32、r bearing plate such that the edgeof the flatjack with the inlet/outlet ports is coincident with the edge of the bearing plate. Place steel spacers around the other edgesof the flatjack. The thickness of the spacers shall be equal0.015 to approximately 10.050 in. (0.3813 times the to 1.27 mm) greate

33、rthan the sum of the combined thickness of the two sheets plus the thickness of inlet/outlet port used in fabrication of the flatjack.Place the upper 2 in. (50 mm) thick bearing plate on top of the shims and flatjack, and align it to be directly above the lower bearingplate. Position the bearing pla

34、te/flatjack/shim assembly on the lower platen such that the centroid of the area of the flatjack is within14 in. (6 mm) of the axis of thrust of the test machine. The calibration setup is illustrated in Fig. 3.7.4 Raise or lower the moveable platen such that the non-moveable platen is both platens a

35、re in contact with the top bearingplate.plates.Apply a pre-load sufficient to provide full contact between the bearing plates and the spacers, equivalent to 10 psi (0.07MPa) over the gross area of the flatjack.7.5 The distance between platens must be held constant during the calibration procedure. F

36、ix the displacement of the testmachine at this point if using a displacement-control machine. If not, attach displacement gauges (mechanical or electrical) suchthat the distance between platens established by the procedures of paragraph 7.4 can be held constant when using a force-controltest machine

37、.7.6 Pressurize and depressurize the flatjack three times over the full operating pressure range. Do not exceed the maximumflatjack operating pressure.7.6.1 While holding the distance between the platens constant, increase the pressure in the flatjack in equal increments to within5 percent of the ma

38、ximum flatjack operating pressure. Use at least 10 equal increments between 0 psi and the maximum flatjackoperating pressure. At each increment, record flatjack hydraulic pressure and force applied by the test machine.7.7 Calculate the load applied by the flatjack as internal pressure times gross fl

39、atjack area. Plot flatjack load versus loadmeasured by the test machine with the flatjack load on the horizontal axis of the plot. The slope of the line equals the flatjackconstant, that is, the conversion factor:FIG. 3 Flatjack Flatjack Calibration Setup (Elevation View)C1197 143Km 5P machineP flat

40、jack (1)7.8 Recalibrate flatjacks after using five times or when distortion appears excessive.8. Procedure8.1 The location where masonry deformability estimates are conducted is dictated by engineering objectives. The basicarrangement is illustrated in Fig. 1. At the desired location or locations th

41、e following steps should be taken.8.2 Select and mark a visible line on the masonry to define the location and length of slots to be formed.8.3 Prepare the slots (see Note 3) (see Section 6) and record the measured slot dimensions. Clean slots of all mortar and brickparticles prior to the insertion

42、of flatjacks. Slots shall be separated by at least five courses of masonry, but not more than 1.5 timesthe length of the flatjack.NOTE 3The location of the slots shall be at least 112 flatjack lengths from wall openings or ends. There should be sufficient masonry above the topslot to resist forces d

43、eveloped during pressurization of the flatjacks.8.4 Attach at least three equally spaced pairs of gauge points or electrical measuring devices as shown in Fig. 1. Centermeasurement points vertically between flatjacks, with a minimum gauge length of 8 in. Locate the measurement points on masonryunits

44、, not at mortar joints. The first and last measurement points should be located at least a distance A/8 in from the ends of theslot, where A is the flatjack length as shown in Fig. 2.8.5 Insert the flatjack into the slot. Shim, as required, to achieve a tight fit and bridge over any interior voids i

45、n the masonry.See Annex A1 for a description of flatjack shims and their use.8.6 Connect hydraulic hoses and fill the flatjacks with hydraulic fluid until pressure begins to develop.8.7 In order to seat the flatjack and any shims, pressurize the flatjack to approximately 50 % of the estimated maximu

46、m flatjackpressure (which corresponds to the estimated maximum compressive strength of the masonry). Reduce the flatjack pressure to zero.8.8 Take initial measurements with mechanical devices (three repetitions) or initialize electrical devices.8.9 Increase pressure slowly. Take displacement measure

47、ments at small increments of pressure. If measurements are to be takenmanually, stop and hold the pressure for at least one minute or until pressure is steady at each incremental step, and recorddisplacements (three repetitions at each gauge point in the case of mechanical measurement devices). Moni

48、tor the flatjackpressure-masonry deformation ratio, p, during the test at each increment of pressure. If failure of the masonry between flatjacksis not desired, the test should stop when the above ratio begins to noticeably decrease.8.10 In older masonry or masonry of low-strength units and low or z

49、ero cement content mortar, flatjacks are capable of loadingthe masonry between them to failure thus establishing maximum strength. However, this may also cause damage to the masonryin areas adjacent to the flatjacks.8.11 Release pressure after the final displacement measurement has been taken.8.12 Disconnect hoses and remove the flatjack. The slot may be filled with mortar or other suitable material of a color andstrength similar to the original mortar.9. Calculation9.1 Calculate stress in the masonry between the flatjacks at any point in the pressurization proces