Comparison of the properties of two types of concretes by non-destructive tests: influence of the geometry of the specimens

Abstract

Most concrete properties are affected by cement and mechanical properties, and some of the durability properties of cement are determined by cement mortars. However, the applications of ultrasound (non-destructive testing) on the determination of the properties of cement mortars are quite limited whatever the method used. Therefore, the required dimensions of the samples as well as the different types of specimens and concrete have not yet been established for special concretes such as self-placing concretes. In this study, non-destructive testing by determination of ultrasonic pulse velocity (UPV) and destructive testing of two types of concretes (regular concrete and self-placing concretes) were determined with different different frequency transducers for different sample sizes and shapes and the relationships between UPV and various concrete properties were studied. As part of the experimental program, three different ultrasonic frequencies (54, 82 and 150 kHz) were used. To this end, mortar mixtures have been prepared with various water / cement ratios having a constant cement content of 450 kg / m3. Cubic, cylindrical and prismatic samples of different sizes were prepared from each mixture of the concretes studied. Keywords: Concretes, SCC, Scale effect; specimen geometry, Compression stress; crushing test; ultrasound