1、Designation: C174/C174M 13C174/C174M 13 American Association StateHighway and Transportation Officials StandardAASHTO No.: T 148Standard Test Method forMeasuring Thickness of Concrete Elements Using DrilledConcrete Cores1This standard is issued under the fixed designation C174/C174M; the number imme
2、diately following the designation indicates the yearof original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon () indicates an editorial change since the last revision or reapproval.This standard ha
3、s been approved for use by agencies of the Department of Defense.1. Scope*1.1 This test method covers the determination of the thickness of a concrete pavement, slab, or structural element by measuringthe length of a core drilled from a concrete structure.1.2 The values stated in either SI units or
4、inch-pound units are to be regarded separately as standard. Within the text, theinch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shallbe used independently of the other.1.3 This standard does not purport to address all of the
5、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 regulatorylimitations prior to use.2. Significance and Use2.1 This test method is used to determine the compl
6、iance of concrete construction with design specifications. It is especiallyimportant in determining the thickness of pavements and other slab construction.3. Apparatus3.1 The apparatus shall consist of a 3-point calipering device that will measure the length of axial elements of the core. Whilethe d
7、etails of the mechanical design are not prescribed, the apparatus shall conform to the requirements of 3.2 to 3.6.2 An exampleof the apparatus is illustrated in Fig. 1.3.2 The apparatus shall be so designed that the specimen will be held with its axis in a vertical position by three symmetricallypla
8、ced supports bearing against the lower end. These supports shall be short posts or studs of hardened steel, and the ends that bearagainst the surface of the specimen shall be rounded to a radius of not less than 6 mm 14 in. and not more than 13 mm 12 in.3.3 The apparatus shall provide for the accomm
9、odation of specimens of different nominal lengths over a range of at least 100to 250 mm 4 to 10 in.3.4 The calipering device shall be so designed that it will be possible to make a length measurement at the center of the upperend of the specimen, and at eight additional points spaced at equal interv
10、als along the circumference of a circle whose center pointcoincides with that of the end area of the specimen and whose radius is not less than one half nor more than three fourths of theradius of the specimen.3.5 The measuring rod or other device that makes contact with the end surface of the speci
11、men for measurement shall berounded to a radius of 3 mm 18 in. The scale on which the length readings are made shall be marked with clear, definite,accurately spaced graduations. The spacing of the graduations shall be 1.0 mm 0.10 in. or a decimal part thereof.1 This test method is under the jurisdi
12、ction of ASTM Committee C09 on Concrete and Concrete Aggregatesand is the direct responsibility of Subcommittee C09.69 onMiscellaneous Tests.Current edition approved Aug. 1, 2013. Published August 2013. Originally approved in 1942. Last previous edition approved in 2012 as C174/C174M12. DOI:10.1520/
13、C0174_C0174M-13.2 For further information relating to the development of this test method and apparatus, reference should be made to the “Project Report on a Study of Methods ofMeasurement of the Length of Cores Drilled from Concrete Structures,” prepared by L. W. Teller for Subcommittee VII on Meth
14、ods and Apparatus for Testing Concrete,of Committee C09, see Proceedings, Am. Soc. Testing Mats., ASTM, Vol 42, 1942.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. Becauseit may
15、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 at the
16、end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.6 The apparatus shall be stable and sufficiently rigid to maintain its shape and alignment without a distortion or deflection ofmore than 0.25 mm 0.01 in. during al
17、l normal measuring operations.3.7 Verification gages: Suitable gages for verification are right circular cylinders with flat ends and a diameter approximatelyequal to the diameter of cores intending to be measured and a length in the range of the required measurements. To accommodatevarious core len
18、gths, gages are available in several lengths. To minimize uncertainty of measurement, the length of the cylinderat the perimeter shall be determined accurately to 0.05 mm 0.002 in. using calibrated measuring instruments. The flatness of theends shall not depart from a plane by more than 0.02 mm 0.00
19、1 in. in any 150 mm 6 in. of cylinders 150 mm 6 in. in diameteror larger, or by more than 0.02 mm 0.001 in. in the diameter of any smaller cylinder.4. Test Specimens4.1 Cores used as specimens for length measurement shall be in every way representative of the concrete in the structure fromwhich they
20、 are removed. The specimen shall be drilled with the axis normal to the surface of the structure, and the ends shall befree from all conditions not typical of the surfaces of the structure. Cores that show abnormal defects or that have been damagedappreciably in the drilling operation shall not be u
21、sed. If a core drilled from a pavement or structure placed on dense-gradedaggregate base course includes particles of the aggregate bonded to the bottom surface of the concrete, the bonded particles shallbe removed by wedging or by chisel and hammer applied so as to expose the lower surface of the c
22、oncrete. If the concrete is placedon an open-graded aggregate base course, the mortar in the concrete may penetrate into the base and surround some particles. Usesufficient force with a wedge or chisel and hammer to remove bonded particles but not such force as to fracture particlessubstantially sur
23、rounded by mortar. If during the removal of bonded aggregate the concrete is broken so that the instructions of5.4 cannot be followed, the core shall not be used for length measurement.5. Procedure5.1 Before any measurements of the core length are made, verify the apparatus with suitable gages, as d
24、efined in 3.7, so thaterrors caused by mechanical imperfections in the apparatus are known. If the difference between the length measured with theapparatus and the known length of the verification gage exceeds 0.25 mm 0.01 in., apply suitable corrections to the core lengthmeasurements.5.2 Place the
25、specimen in the measuring apparatus with the smooth end of the core, that is, the end that represents the uppersurface of a pavement slab or a formed surface in the case of other structures, placed down so as to bear against the threeFIG. 1 Core Measuring ApparatusC174/C174M 132hardened-steel suppor
26、ts. So place the specimen on the supports that the central measuring position of the measuring apparatus isdirectly over the midpoint of the upper end of the specimen.5.3 Make nine measurements of the length on each specimen, one at the central position and one each at eight additionalpositions spac
27、ed at equal intervals along the circumference of the circle of measurement. Read each of these nine measurementsto the nearest 1.0 mm 0.05 in.5.4 If, in the course of the measuring operation, it is discovered that at one or more of the measuring points the surface of thespecimen is not representativ
28、e of the general plane of the core end because of a small projection or depression, the specimen shallbe rotated slightly about its axis and a complete set of nine measurements made with the specimen in the new position. With coresfrom pavements placed over open-graded aggregate bases the foregoing
29、provisions frequently cannot be met because of the greatnumber of projections or voids on the bottom surface.6. Report6.1 The individual observations shall be recorded to the nearest 1.0 mm 0.05 in., and the average of the nine measurementsexpressed to the nearest 1.0 mm 0.05 in. shall be reported a
30、s the length of the concrete core.7. Precision and Bias7.1 Precision:7.1.1 3-Point CaliperNo statement is made about the precision of this test procedure. An interlaboratory test program for thedetermination of core length by this procedure is being studied by Subcommittee C09.69 and will be include
31、d in a later revisionof this test method.7.2 BiasSince there are not acceptable reference cores suitable for determining the bias of these procedures, no statement onbias is being made.8. Keywords8.1 3-point caliper; concrete; cores; length measurement; thickness measurementSUMMARY OF CHANGESCommitt
32、ee C09 has identified the location of selected changes to this test method since the last issue,C174/C174M12, that may impact the use of this test method. (Approved August 1, 2013)(1) Changed section 6.1.(2) Changed section 5.1 and added section 3.7.Committee C09 has identified the location of selec
33、ted changes to this test method since the last issue,C174/C174M06, that may impact the use of this test method. (Approved July 1, 2012)(1) Deleted Footnote 3.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standa
34、rd. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewe
35、d every five years andif not revised, either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible t
36、echnical 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 Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
37、hocken, 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).C174/C174M 133
