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Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
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Q. According to Provision 1.7.4.2 of ACI 301-20, a rebound hammer cannot be used for in-place strength testing. Does ACI recommend any other nondestructive testing (NDT) method for in-place strength evaluation? A. You are correct, Provision 1.7.4.2 of ACI 301-20 allows use of a rebound hammer in accordance with ASTM C805/C805M, if specified by the Architect/Engineer, only “to evaluate uniformity of in-place concrete or to select areas to be cored.” The same restriction applies to the pulse velocity method per ASTM C597. At the same time, Provision 1.7.5.3(a) states: “Results of in-place strength tests will be evaluated by Architect/Engineer and are valid only if tests are conducted using properly calibrated equipment in accordance with recognized standard procedures and an acceptable correlation between test results and concrete compressive strength is established and submitted.” However, no specific NDT methods or equipment for in-place strength evaluation are listed. For a review of in-place methods for estimating concrete strength, refer to ACI 228.1R. References: ACI 301-20; ACI 228.1R-19; ASTM C805 / C805M; ASTM C597 Topics in Concrete: Nondestructive Testing; Specifications
Q. According to Provision 1.7.4.2 of ACI 301-20, a rebound hammer cannot be used for in-place strength testing. Does ACI recommend any other nondestructive testing (NDT) method for in-place strength evaluation?
A. You are correct, Provision 1.7.4.2 of ACI 301-20 allows use of a rebound hammer in accordance with ASTM C805/C805M, if specified by the Architect/Engineer, only “to evaluate uniformity of in-place concrete or to select areas to be cored.” The same restriction applies to the pulse velocity method per ASTM C597. At the same time, Provision 1.7.5.3(a) states: “Results of in-place strength tests will be evaluated by Architect/Engineer and are valid only if tests are conducted using properly calibrated equipment in accordance with recognized standard procedures and an acceptable correlation between test results and concrete compressive strength is established and submitted.” However, no specific NDT methods or equipment for in-place strength evaluation are listed. For a review of in-place methods for estimating concrete strength, refer to ACI 228.1R.
References: ACI 301-20; ACI 228.1R-19; ASTM C805 / C805M; ASTM C597
Topics in Concrete: Nondestructive Testing; Specifications
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