1、Designation:C174/C174M06 Designation: C174/C174M 12American 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
2、number immediately 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
3、standard has 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 S
4、I units or 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
5、all of the 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 determin
6、e the compliance 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.
7、 Whilethe details of the mechanical design are not prescribed, the apparatus shall conform to the requirements of 3.2 to 3.6.2An 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 symmet
8、ricallyplaced 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
9、the accommodation 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 eq
10、ual intervals 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
11、 the specimen 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.3.6 The apparatus shall be st
12、able 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.4. Test Specimens4.1 Cores used as specimens for length measurement shall be in every way representative of the concrete in the struc
13、ture fromwhich they are removed. The specimen shall be drilled with the axis normal to the surface of the structure, and the ends shall be1This test method is under the jurisdiction of ASTM Committee C09 on Concrete and Concrete Aggregates and is the direct responsibility of Subcommittee C09.69 onMi
14、scellaneous Tests.Current edition approved Feb.July 1, 2006.2012. Published February 2006.September 2012. Originally approved in 1942. Last previous edition approved in 19972006 asC174/C174M97.C174/C174M06. DOI: 10.1520/C0174_C0174M-0612.2For further information relating to the development of this t
15、est 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 Methods and Apparatus for Testing Concrete,of Committee C09, see Proceedings, Am. S
16、oc. Testing Mats., ASTM, Vol 42, 1942.1This 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
17、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 end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO B
18、ox C700, West Conshohocken, PA 19428-2959, United States.free 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 used. If a core drilled from a pavement or structure placed on
19、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 concrete. If the concrete is placedon an open-graded aggregate
20、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 surrounded by mortar. If during the removal of bonded aggregate t
21、he 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, calibrate the apparatus with suitable gages so that errors caused bymechanical imperfections in the apparatu
22、s are known. When these errors exceed 0.25 mm 0.01 in., apply suitable corrections tothe core length measurements.5.2 Place the 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
23、 other structures, placed down so as to bear against the threehardened-steel supports. 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 s
24、pecimen, one at the central position and one each at eight additionalpositions spaced 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
25、one or more of the measuring points the surface of thespecimen is not representative 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 positi
26、on. With coresfrom pavements placed over open-graded aggregate bases the foregoing 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 o
27、f the nine measurementsexpressed to the nearest 1.0 mm 0.1 in. shall be reported as the length of the concrete core.FIG. 1 Core Measuring ApparatusC174/C174M 1227. Precision and Bias7.1 Precision:7.1.1 3-Point CaliperNo statement is made about the precision of this test procedure. An interlaboratory
28、 test program for thedetermination of core length by this procedure is being studied by Subcommittee C09.69 and will be included 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
29、 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,C174/C174M97,C174/C174M06, that may impact the use of this test method. (Appr
30、oved FebruaryJuly 1,2006)2012)(1) Added Keywords. ) Deleted Footnote 3.ASTM 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
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33、ived 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) o
34、f 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 123
