1、Designation: C174/C174M 16 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 immediately follo
2、wing 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 has been approv
3、ed for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test method covers the determination of the thick-ness of a concrete pavement, slab, or structural element usingdrilling cores.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as stand
4、ard. Within the text, theinch-pound 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 t
5、heresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C42/C42M Test Method for Obtaining and Testing DrilledCores and Sawed Beams of Concre
6、teC125 Terminology Relating to Concrete and Concrete Ag-gregatesC670 Practice for Preparing Precision and Bias Statementsfor Test Methods for Construction Materials2.2 AASHTO Standards:3AASHTO T148 Method of Test for Measuring Length ofDrilled Concrete Cores3. Terminology3.1 Definitions:3.1.1 For de
7、finitions of terms used in this test method, referto Terminology C125.4. Significance and Use4.1 This test method is used to determine the compliance ofconcrete construction with design specifications and is com-monly used in determining the thickness of pavements andother slab construction. This te
8、st method requires that at leastone end of the core be a finished or formed surface.5. Apparatus5.1 The apparatus shall consist of a base plate with threeposts to support the core in a vertical direction, and top plate orother means of establishing a plane that is parallel to and ameasured distance
9、from the plane defined by the supportingposts. The apparatus includes a measuring rod as described in5.5 or other means to determine the length of axial elements ofthe core. While the details of the mechanical design are notprescribed, the apparatus shall conform to the requirements of5.2 5.6. An ex
10、ample of an apparatus is illustrated in Fig. 1.5.2 The base of the apparatus shall be so designed that thecore will be held with its axis in a vertical position by threesymmetrically placed supports bearing against the lower end ofthe core. These supports shall be short posts or studs ofhardened ste
11、el, and the ends that bear against the surface of thecore shall be rounded to a radius of not less than 6 mm 14 in.and not more than 13 mm 12 in.5.3 The apparatus shall provide for the accommodation ofcores of different nominal lengths over a range of at least 100to 250 mm 4 to 10 in.5.4 The top pla
12、te or other means of measuring shall be sodesigned that it will be possible to make a length measurementat the center of the upper end of the core, and at eightadditional points spaced at equal intervals along the circum-ference of a circle whose center point coincides with that of theend area of th
13、e core and whose radius is not less than one halfnor more than three fourths of the radius of the core.1This test method is under the jurisdiction of ASTM Committee C09 onConcrete and Concrete Aggregates and is the direct responsibility of SubcommitteeC09.61 on Testing for Strength.Current edition a
14、pproved June 1, 2016. Published July 2016. Originally approvedin 1942. Last previous edition approved in 2013 as C174/C174M 13. DOI:10.1520/C0174_C0174M-16.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of AST
15、MStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American Association of State Highway and TransportationOfficials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,http:/www.transportation.org.*A Summary of Changes sectio
16、n appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.5 The measuring rod or other device that makes contactwith the end surface of the core for measurement shall berounded to a radius of 3 mm 18 in. T
17、he scale on themeasuring rod shall be marked with clear, definite, accuratelyspaced graduations. The spacing of the graduations shall be1.0 mm 0.10 in. or a decimal part thereof. The measuring rodshall be used to measure the distance from the bottom of thetop plate to the top of the core (see Fig. 1
18、).5.6 The apparatus shall 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.5.7 Verification GagesSuitable gauges for verification areright circular cylinders with flat ends and a
19、diameter approxi-mately equal to the diameter of cores intending to be measuredand a length in the range of the required measurements. Toaccommodate various core lengths, gauges are available inseveral lengths. To minimize uncertainty of measurement, thelength of the cylinder at the perimeter shall
20、be determinedaccurately to 0.05 mm 0.002 in. using calibrated measuringinstruments. The flatness of the ends shall not depart from aplane by more than 0.02 mm 0.001 in. in any 150 mm 6 in.of cylinders 150 mm 6 in. in diameter or larger, or by morethan 0.02 mm 0.001 in. in the diameter of any smaller
21、cylinder.6. Test Specimens6.1 Cores used for length measurement shall be obtained inaccordance with Test Method C42/C42M. The core shall bedrilled with the axis normal to the surface of the structure.6.2 If a core drilled from a pavement or structure placed onaggregate base course includes particles
22、 of the aggregate basebonded to the bottom surface of the concrete, the bondedparticles shall be removed to expose the lower surface of theconcrete. If during the removal of bonded aggregate, theconcrete is broken so that the measurements obtained in 7.3 arenot representative of the original core le
23、ngth, the core shall notbe used for length measurement.6.3 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 toremove bonded particles but not such force as to fractureparticles su
24、bstantially surrounded by mortar. If during theremoval of bonded aggregate the concrete is broken so that themeasurements obtained in 7.3 are not representative of theoriginal core length, the core shall not be used for lengthmeasurement.7. Procedure7.1 Before any measurements of the core length are
25、 made,verify the apparatus with suitable gauges, as defined in 5.7,sothat errors caused by mechanical imperfections in the apparatusare known. If the difference between the length measured withthe apparatus and the known length of the verification gaugeexceeds 0.25 mm 0.01 in., apply suitable correc
26、tions to thecore length measurements.7.2 Place the core in the measuring apparatus with the flatend of the core, that is, the end that represents the upper surfaceof a pavement slab or a formed surface in the case of otherstructures, placed down so as to bear against the threehardened-steel supports
27、. Place the core on the supports so thatthe central measuring position of the measuring apparatus isdirectly over the center of the upper end of the core.7.3 Make nine measurements from the bottom of the topplate or other established plane to the top of the core, one at thecentral position and one e
28、ach at eight additional positionsspaced at equal intervals along the circumference of the circleof measurement. Read each of these nine measurements to thenearest 1.0 mm 0.05 in. Average the nine measurements andcalculate the length of the core using this average and theknown distance between the tw
29、o established planes.7.4 If, in the course of the measuring operation, it isdiscovered that at one or more of the measuring points thesurface of the core is not representative of the general plane ofthe core end because of a small projection or depression, thecore shall be rotated slightly about its
30、 axis and a complete setof nine measurements made with the core in the new position.With cores from pavements placed over open-graded aggregatebases the foregoing provisions frequently cannot be metbecause of the great number of projections or voids on thebottom surface.8. Report8.1 Report the lengt
31、h of the core to the nearest 1.0 mm0.05 in.FIG. 1 An Example of Suitable Measuring ApparatusC174/C174M 1629. Precision and Bias9.1 PrecisionSingle-operator and multilaboratory preci-sion indexes are based on the results of an interlaboratory studyconducted by the NCHRP.4Cores, representative of diff
32、erentconcrete pavement test sections, either 100 mm 4 in. or150 mm 6 in. in nominal diameter with lengths rangingfrom 100 mm 4 in. to 300 mm 12 in. were used for thestudy. Testing was performed in accordance with AASHTOT148 which uses the same apparatus and measurement proce-dures as Test Method C17
33、4/C174M. Measurements were madeto the nearest 0.1 mm. The inch-pound values in Table 1were obtained by mathematical conversion of the reported SIvalues and rounded to two decimal places.9.2 BiasBecause there are no reference cores suitable fordetermining the bias of these procedures, no statement on
34、 biasis being made.10. Keywords10.1 concrete; core length measuring apparatus; cores;length measurement; thickness measurementSUMMARY OF CHANGESCommittee C09 has identified the location of selected changes to this standard since the last issue(C174/C174M 13) that may impact the use of this standard.
35、 (Approved June 1, 2016.)(1) Corrected wording and removed arbitrary wording.(2) Added Section 2, Referenced Documents, and Section 3,Terminology.(3) Revised and renamed Fig. 1.(4) Added precision statement, 9.1.ASTM International takes no position respecting the validity of any patent rights assert
36、ed in connection with any item mentionedin this 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 t
37、he responsible technical committee and must 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
38、 careful consideration at a meeting of theresponsible 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 Interna
39、tional, 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
40、the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ H., 2010, “Precision Estimates of AASHTO T148: Measuring Length ofDrilled Concrete Cores”; NCHRP Web-
41、Only Document 165, http:/onlinepubs.trb.org/onlinepubs/nchrp/nchrp_w165.pdfTABLE 1 Indexes of PrecisionNominal SpecimenDiameterStandardDeviationAcceptable Difference BetweenTwo ResultsASingle-operatorPrecision:100 mm 4 in. 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.Mu
42、lt-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.AThese values represent the d2s limits described in Practice C670.NOTE 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 163
