METHOD AND APPARATUS FOR ESTIMATION OF STRENGTH OF CONCRETE

PROBLEM TO BE SOLVED: To estimate the compressive strength of concrete with high accuracy by a nondestructive testing method. SOLUTION: The repulsion degree Rs on the surface of the concrete as a measuring object is measured by a concrete test hammer 14, and its carbonization depth C is measured by a carbonization-depth measuring machine 16. In an apparatus mainframe 12, a surface-hardness correction coefficient β as the ratio of the hardness in a carbonized surface part of the concrete to the hardness of the noncarbonized inside is stored so as to be related to the carbonization depth C of the concrete. As the correction coefficient β, a value corresponding to a measured value of the carbonization depth C is set, a correction repulsion degree Ri corresponding to the repulsion degree at the inside of the concrete is found by Ri=β×Rs-(1-β)×b/a, and the compressive strength Fc is estimated and computed based on the correction repulsion degree Ri. COPYRIGHT: (C)2003,JPO