Anisotropy of reinforced concrete from geophysical methods

Abstract

Anisotropy is expressed as the direction-dependent change of material properties and it is a very important parameter to the correct determination of the concrete quality. For the aim of determining the concrete anisotropy, geophysical measurements in the study were carried out on the reinforced concrete samples with different strengths, before concrete strengths were determined from Uniaxial Compressive Strength test. Since the propagation direction of concrete pores and saturation type of it is important parameters in affecting the concrete anisotropy, prepared samples were cured as oven-dried, water-saturated, and dried in outside. Thus, the effects of curing conditions on the anisotropy of reinforced concrete were investigated by geophysical measurements. For this purpose, ultrasonic P and S wave measurements were made on two opposite surfaces of cubic samples with different reinforcement diameters. In addition, a total of 8 resistivity measurements were performed by taking two diagonal measurements on each surface in except of reinforced surfaces of the sample. The velocity and resistivity anisotropies of samples were determined by using the anisotropy relations given in the literature. As a result, it is determined that while reinforcement diameter has no distinctive effect on anisotropy, curing conditions are especially very effective on resistivity anisotropy.