ASTM C174/C174M-17

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Designation: C174/C174M − 16 C174/C174M − 17 American Association State
Highway and Transportation Officials Standard
AASHTO No.: T 148
Standard Test Method for
Measuring Thickness of Concrete Elements Using Drilled
Concrete Cores
This standard is issued under the fixed designation C174/C174M; the number immediately following the designation indicates the year
of 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 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 drilling
cores.
1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the
inch-pound units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system shall
be used independently of the other.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
C42/C42M Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete
C125 Terminology Relating to Concrete and Concrete Aggregates
C670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials
2.2 AASHTO Standards:
AASHTO T148 Method of Test for Measuring Length of Drilled Concrete Cores
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms used in this test method, refer to Terminology C125.
4. Significance and Use
4.1 This test method is used to determine the compliance of concrete construction with design specifications and is commonly
used in determining the thickness of pavements and other slab construction. This test method requires that at least one end of the
core be a finished or formed surface.
5. Apparatus
5.1 The apparatus shall consist of a base plate with three posts to support the core in a vertical direction, and top plate or other
means of establishing a plane that is parallel to and a measured distance from the plane defined by the supporting posts. The
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 on
Testing for Strength.
Current edition approved June 1, 2016May 1, 2017. Published July 2016July 2017. Originally approved in 1942. Last previous edition approved in 20132016 as
C174/C174M – 13.C174/C174M – 16. DOI: 10.1520/C0174_C0174M-16.10.1520/C0174_C0174M-17.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from American Association of State Highway and Transportation Officials (AASHTO), 444 N. Capitol St., NW, Suite 249, Washington, DC 20001,
http://www.transportation.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C174/C174M − 17
apparatus includes a measuring rod as described in 5.5 or other means to determine the length of axial elements of the core. While
the details of the mechanical design are not prescribed, the apparatus shall conform to the requirements of 5.2 – 5.6. An example
of 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 three
symmetrically placed supports bearing against the lower end of the core. These supports shall be short posts or studs of hardened
steel, and the ends that bear against the surface of the core shall be rounded to a radius of not less than 6 mm [ ⁄4 in.] and not more
than 13 mm [ ⁄2 in.].
5.3 The apparatus shall provide for the accommodation of cores of different nominal lengths over a range of at least 100 to 250
mm [4 to 10 in.].
5.4 The top plate or other means of measuring shall be so designed that it will be possible to make a length measurement at
the center of the upper end of the core, and at eight additional points spaced at equal intervals along the circumference of a circle
whose center point coincides with that of the end area of the core and whose radius is not less than one half nor more than three
fourths 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 rounded
to a radius of 3 mm [ ⁄8 in.]. The scale on the measuring rod 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. not be greater than 1.0 mm or 0.10 in. The
measuring 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 The apparatus shall be stable and sufficiently rigid to maintain its shape and alignment without a distortion or deflection of
more than 0.25 mm [0.01 in.] during all normal measuring operations.
5.7 Verification Gages—Gauges—Suitable gauges gauge blocks for verification are right circular cylinders with flat ends and
a diameter approximately equal to the diameter of cores intending to be measured and a length in the range of the required
measurements. measurements (Note 1To accommodate various core lengths, gauges are available in several lengths. To ). To
minimize uncertainty of measurement, the length of the cylinder at the perimeter shall be determined accurately to 0.05 mm [0.002
in.] using calibrated measuring instruments. The flatness of the ends shall not depart from a plane 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 more than 0.02 mm [0.001 in.] in the diameter
of any smaller cylinder.
NOTE 1—To permit verification of different core length measurements, multiple verification cylinders of different lengths may be used.
FIG. 1 An Example of
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