1、Designation: C 174/C 174M 06American 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 C 174/C 174M; the number immediately fo
2、llowing 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test me
3、thod covers the determination of the thick-ness of a concrete pavement, slab, or structural element bymeasuring the length of a core drilled from a concretestructure.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard. Within the text, theinch-pound
4、units are shown in brackets. The values stated ineach system are not exact equivalents; therefore, each systemshall be used independently of the other.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
5、 standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Significance and Use2.1 This test method is used to determine the compliance ofconcrete construction with design specifications. It is espe-cially important in d
6、etermining the thickness of pavements andother slab construction.3. Apparatus3.1 The apparatus shall consist of a 3-point caliperingdevice that will measure the length of axial elements of thecore. While the details of the mechanical design are notprescribed, the apparatus shall conform to the requi
7、rements of3.2 to 3.6.2An example of the apparatus is illustrated in Fig. 1.33.2 The apparatus shall be so designed that the specimenwill be held with its axis in a vertical position by threesymmetrically placed supports bearing against the lower end.These supports shall be short posts or studs of ha
8、rdened steel,and the ends that bear against the surface of the specimen shallbe rounded to a radius of not less than 6 mm 14 in. and notmore than 13 mm 12 in.3.3 The apparatus shall provide for the accommodation ofspecimens of different nominal lengths over a range of at least100 to 250 mm 4 to 10 i
9、n.3.4 The calipering device shall be so designed that it will bepossible to make a length measurement at the center of theupper end of the specimen, and at eight additional pointsspaced at equal intervals along the circumference of a circle1This test method is under the jurisdiction of ASTM Committe
10、e C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.69 on Miscellaneous Tests.Current edition approved Feb. 1, 2006. Published February 2006. Originallyapproved in 1942. Last previous edition approved in 1997 as C 174/C 174M 97.2For further information relati
11、ng to the development of this test method andapparatus, reference should be made to the “Project Report on a Study of Methodsof Measurement of the Length of Cores Drilled from Concrete Structures,” preparedby L. W. Teller for Subcommittee VII on Methods and Apparatus for TestingConcrete, of Committe
12、e C09, see Proceedings, Am. Soc. Testing Mats., ASTM, Vol42, 1942.3The sole source of supply of the apparatus known to the committee at this timeis Humboldt Mfg. Co., 7300 West Agatite, Norridge, IL 80656-4704, Catalog No.H-2939. If you are aware of alternative suppliers, please provide this informa
13、tion toASTM Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee, which you may attend.FIG. 1 Core Measuring Apparatus1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, P
14、O Box C700, West Conshohocken, PA 19428-2959, United States.whose center point coincides with that of the end area of thespecimen and whose radius is not less than one half nor morethan three fourths of the radius of the specimen.3.5 The measuring rod or other device that makes contactwith the end s
15、urface of the specimen for measurement shall berounded to a radius of 3 mm 18 in. The scale on which thelength readings are made shall be marked with clear, definite,accurately spaced graduations. The spacing of the graduationsshall be 1.0 mm 0.10 in. or a decimal part thereof.3.6 The apparatus shal
16、l be stable and sufficiently rigid tomaintain its shape and alignment without a distortion ordeflection of more than 0.25 mm 0.01 in. during all normalmeasuring operations.4. Test Specimens4.1 Cores used as specimens for length measurement shallbe in every way representative of the concrete in the s
17、tructurefrom which they are removed. The specimen shall be drilledwith the axis normal to the surface of the structure, and theends shall be free from all conditions not typical of the surfacesof the structure. Cores that show abnormal defects or that havebeen damaged appreciably in the drilling ope
18、ration shall not beused. If a core drilled from a pavement or structure placed ondense-graded aggregate base course includes particles of theaggregate bonded to the bottom surface of the concrete, thebonded particles shall be removed by wedging or by chisel andhammer applied so as to expose the lowe
19、r surface of theconcrete. If the concrete is placed on an open-graded aggregatebase course, the mortar in the concrete may penetrate into thebase and surround some particles. Use sufficient force with awedge or chisel and hammer to remove bonded particles butnot such force as to fracture particles s
20、ubstantially surroundedby mortar. If during the removal of bonded aggregate theconcrete is broken so that the instructions of 5.4 cannot befollowed, the core shall not be used for length measurement.5. Procedure5.1 Before any measurements of the core length are made,calibrate the apparatus with suit
21、able gages so that errors causedby mechanical imperfections in the apparatus are known.When these errors exceed 0.25 mm 0.01 in., apply suitablecorrections to the core length measurements.5.2 Place the specimen in the measuring apparatus with thesmooth end of the core, that is, the end that represen
22、ts the uppersurface of a pavement slab or a formed surface in the case ofother structures, placed down so as to bear against the threehardened-steel supports. So place the specimen on the supportsthat the central measuring position of the measuring apparatusis directly over the midpoint of the upper
23、 end of the specimen.5.3 Make nine measurements of the length on each speci-men, one at the central position and one each at eight additionalpositions spaced at equal intervals along the circumference ofthe circle of measurement. Read each of these nine measure-ments to the nearest 1.0 mm 0.05 in.5.
24、4 If, in the course of the measuring operation, it isdiscovered that at one or more of the measuring points thesurface of the specimen is not representative of the generalplane of the core end because of a small projection ordepression, the specimen shall be rotated slightly about its axisand a comp
25、lete set of nine measurements made with thespecimen in the new position. With cores from pavementsplaced over open-graded aggregate bases the foregoing provi-sions frequently cannot be met because of the great number ofprojections or voids on the bottom surface.6. Report6.1 The individual observatio
26、ns shall be recorded to thenearest 1.0 mm 0.05 in., and the average of the ninemeasurements expressed to the nearest 1.0 mm 0.1 in. shallbe reported as the length of the concrete core.7. Precision and Bias7.1 Precision:7.1.1 3-Point CaliperNo statement is made about theprecision of this test procedu
27、re. An interlaboratory test pro-gram for the determination of core length by this procedure isbeing studied by Subcommittee C09.69 and will be included ina later revision of this test method.7.2 BiasSince there are not acceptable reference coressuitable for determining the bias of these procedures,
28、nostatement on bias is being made.8. Keywords8.1 3-point caliper; concrete; cores; length measurement;thickness measurementSUMMARY OF CHANGESCommittee C09 has identified the location of selected changes to this test method since the last issue,C 174/C 174M 97, that may impact the use of this test me
29、thod. (Approved February 1, 2006)(1) Added Keywords.C 174/C 174M 062ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any
30、 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 reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are in
31、vited 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 technical committee, which you may attend. If you feel that your comments have not receive
32、d 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 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 174/C 174M 063
