1、Designation: C174/C174M 16C174/C174M 17 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 U.S. Department of Defense.1. Scope*1.1 This test method covers the determination of the thickness of a concrete pavement, slab, or structural element using drillingcores.1.2 The values stated in either SI units or inch-pound units are to be regarded separa
4、tely 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 safety concerns, if any, associated with i
5、ts 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.1.4 This international standard was developed in accordance with internationally recognized principles on standardiz
6、ationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C42/C42M Test Method for Obtaining and Testing Drille
7、d Cores and Sawed Beams of ConcreteC125 Terminology Relating to Concrete and Concrete AggregatesC670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials2.2 AASHTO Standards:3AASHTO T148 Method of Test for Measuring Length of Drilled Concrete Cores3. Termi
8、nology3.1 Definitions:3.1.1 For definitions of terms used in this test method, refer to Terminology C125.4. Significance and Use4.1 This test method is used to determine the compliance of concrete construction with design specifications and is commonlyused in determining the thickness of pavements a
9、nd other slab construction. This test method requires that at least one end of thecore be a finished or formed surface.5. Apparatus5.1 The apparatus shall consist of a base plate with three posts to support the core in a vertical direction, and top plate or othermeans of establishing a plane that is
10、 parallel to and a measured distance from the plane defined by the supporting posts. The1 This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.61 onTesting for Strength.Current edition approved June
11、1, 2016May 1, 2017. Published July 2016July 2017. Originally approved in 1942. Last previous edition approved in 20132016 asC174/C174M 13.C174/C174M 16. DOI: 10.1520/C0174_C0174M-16.10.1520/C0174_C0174M-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer S
12、ervice at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 Available from American Association of State Highway and Transportation Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:
13、/www.transportation.org.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 not be technically possible to adequately depict all changes accurately, ASTM recommends that
14、 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 end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Co
15、nshohocken, PA 19428-2959. United States1apparatus includes a measuring rod as described in 5.5 or other means to determine the length of axial elements of the core. Whilethe details of the mechanical design are not prescribed, the apparatus shall conform to the requirements of 5.2 5.6. An exampleof
16、 an apparatus is illustrated in Fig. 1.5.2 The base of the apparatus shall be so designed that the core will be held with its axis in a vertical position by threesymmetrically placed supports bearing against the lower end of the core. These supports shall be short posts or studs of hardenedsteel, an
17、d the ends that bear against the surface of the core shall be rounded to a radius of not less than 6 mm 14 in. and not morethan 13 mm 12 in.5.3 The apparatus shall provide for the accommodation of cores of different nominal lengths over a range of at least 100 to 250mm 4 to 10 in.5.4 The top plate o
18、r other means of measuring shall be so designed that it will be possible to make a length measurement atthe center of the upper end of the core, and at eight additional points spaced at equal intervals along the circumference of a circlewhose center point coincides with that of the end area of the c
19、ore and whose radius is not less than one half nor more than threefourths of the radius of the core.5.5 The measuring rod or other device that makes contact with the end surface of the core for measurement shall be roundedto a radius of 3 mm 18 in. The scale on the measuring rod shall be marked with
20、 clear, definite, accurately spaced graduations.The spacing of the graduations shall be 1.0 mm 0.10 in. or a decimal part thereof. not be greater than 1.0 mm or 0.10 in. Themeasuring rod shall be used to measure the distance from the bottom of the top plate to the top of the core (see Fig. 1).5.6 Th
21、e 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 all normal measuring operations.5.7 Verification GagesGaugesSuitable gauges gauge blocks for verification are right circular cylinders with fl
22、at ends anda diameter approximately equal to the diameter of cores intending to be measured and a length in the range of the requiredmeasurements. measurements (Note 1To accommodate various core lengths, gauges are available in several lengths. To ). Tominimize uncertainty of measurement, the length
23、 of the cylinder at the perimeter shall be determined accurately to 0.05 mm 0.002in. using calibrated measuring instruments. The flatness of the ends shall not depart from a plane by more than 0.02 mm 0.001in. in any 150 mm 6 in. of cylinders 150 mm 6 in. in diameter or larger, or by more than 0.02
24、mm 0.001 in. in the diameterof any smaller cylinder.NOTE 1To permit verification of different core length measurements, multiple verification cylinders of different lengths may be used.FIG. 1 An Example of Suitable Measuring ApparatusC174/C174M 1726. Test Specimens6.1 Cores used for length measureme
25、nt shall be obtained in accordance with Test Method C42/C42M. The core shall be drilledwith the axis normal to the surface of the structure.6.2 If a core drilled from a pavement or structure placed on aggregate base course includes particles of the aggregate basebonded to the bottom surface of the c
26、oncrete, the bonded particles shall be removed to expose the lower surface of the concrete.If during the removal of bonded aggregate, the concrete is broken so that the measurements obtained in 7.3 are not representativeof the original core length, the core shall not be used for length measurement.6
27、.3 If the concrete is placed on an open-graded aggregate base course, the mortar in the concrete may penetrate into the baseand surround some particles. Use sufficient force to remove bonded particles but not such force as to fracture particles substantiallysurrounded by mortar. If during the remova
28、l of bonded aggregate the concrete is broken so that the measurements obtained in 7.3are not representative of the original core length, the core shall not be used for length measurement.7. Procedure7.1 Before any measurements of the core length are made, verify the apparatus with suitable gauges, a
29、s defined in 5.7, 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 gauge exceeds 0.25 mm 0.01 in., apply suitable corrections to the core lengthmeasurements.7.2 Place
30、the core in the measuring apparatus with the flat end of the core, that is, the end that represents the upper surface ofa pavement slab or a formed surface in the case of other structures, placed down so as to bear against the three hardened-steelsupports. Place the core on the supports so that the
31、central measuring position of the measuring apparatus is directly over the centerof the upper end of the core.7.3 Make nine measurements from the bottom of the top plate or other established plane to the top of the core, one at the centralposition and one each at eight additional positions spaced at
32、 equal intervals along the circumference of the circle of measurement.Read each of these nine measurements to the nearest 1.0 mm 0.05 in. Average the nine measurements and calculate the lengthof the core using this average and the known distance between the two established planes.7.4 If, in the cour
33、se of the measuring operation, it is discovered that at one or more of the measuring points the surface of thecore is not representative of the general plane of the core end because of a small projection or depression, the core shall be rotatedslightly about its axis and a complete set of nine measu
34、rements made with the core in the new position. With cores from pavementsplaced over open-graded aggregate bases the foregoing provisions frequently cannot be met because of the great number ofprojections or voids on the bottom surface.8. Report8.1 Report the length of the core to the nearest 1.0 mm
35、 0.05 in.9. Precision and Bias9.1 PrecisionSingle-operator and multilaboratory precision indexes are based on the results of an interlaboratory studyconducted by the NCHRP.4 Cores, representative of different concrete pavement test sections, either 100 mm 4 in. or 150 mm6 in. in nominal diameter wit
36、h lengths ranging from 100 mm 4 in. to 300 mm 12 in. were used for the study. Testing wasperformed in accordance with AASHTO T148 which uses the same apparatus and measurement procedures as Test MethodC174/C174M. Measurements were made to the nearest 0.1 mm. The inch-pound values in Table 1 were obt
37、ained by mathemati-cal conversion of the reported SI values and rounded to two decimal places.9.2 BiasBecause there are no reference cores suitable for determining the bias of these procedures, no statement on bias isbeing made.10. Keywords10.1 concrete; core length measuring apparatus; cores; lengt
38、h measurement; thickness measurement4 Azari, H., 2010, “Precision Estimates of AASHTO T148: Measuring Length of Drilled Concrete Cores”; NCHRP Web-Only Document 165, http:/onlinepubs.trb.org/onlinepubs/nchrp/nchrp_w165.pdfC174/C174M 173SUMMARY OF CHANGESCommittee C09 has identified the location of s
39、elected changes to this standard since the last issue(C174/C174M 13C174/C174M 16) that may impact the use of this standard. (Approved May 1, 2017June 1,2016.).)(1) Corrected wording and removed arbitrary wording. Clarified description of markings on measuring rod (5.5).(2) Added SectionCorrected spe
40、lling 2, Referenced Documents, and Sectionof “gages” and use 3, Terminology.of multiple gaugeblocks (5.7).(3) Revised and renamed Fig. 1.(4) Added precision statement, 9.1.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned
41、 inthis standard. 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 m
42、ust be reviewed 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 th
43、eresponsible 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 Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C70
44、0, 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). Permissio
45、n rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 1 Indexes of PrecisionNominal SpecimenDiameterStandardDeviationAcceptable Difference BetweenTwo ResultsASingle-operatorPrecision:100 mm 4 in.
46、0.4 mm 0.02 in. 1.0 mm 0.04 in.150 mm 6 in. 0.7 mm 0.03 in. 1.9 mm 0.07 in.Mult-laboratoryPrecision:100 mm 4 in. 0.9 mm 0.04 in. 2.4 mm 0.09 in.150 mm 6 in. 1.8 mm 0.07 in. 4.9 mm 0.19 in.A These values represent the d2s limits described in Practice C670.C174/C174M 174NOTE 1An interlaboratory test program for determining the precisionof core length by this test method for various end conditions is beingstudied by Subcommittee C09.61 and the results will be included in a laterrevision of this test method.C174/C174M 175
