Experimental and theoretical investigation of interfacial losses in concrete with laser ultrasonics

Abstract

The strength of concrete is controlled by three factors: strength of the matrix, strength of the aggregate, and strength of the bond between matrix and aggregate. It is well known that material interfaces play an important role in the overall mechanical behavior of bonded materials e.g concrete. Reflected and transmitted ultrasonic waves have been used to develop non-destructive ultrasonic techniques to examine the size and location of flaws and to provide measurements of the internal structure of concrete among other things. In the studies of elastic wave scattering by interfaces, it is generally assumed that the inclusion is perfectly bonded to the surrounding matrix material. It does, however, frequently happen that the bond is imperfect whereby reducing the stiffness and hence the strength of the material.