Investigation of the acoustoelastic effect in structural masonry elements of concrete blocks

Abstract

The theory of acoustoelasticity relates the propagation velocity of elastic waves in a solid and its stress state. Even though researches applying the theory of acoustoelasticity to rocks, concrete and metallic elements have already been published, the development of this theory applied to masonry elements is not significant. The objective of this project is to investigate the application of the acoustoelastic effect to structural masonry elements of concrete blocks. This research will be divided in three stages approaching numerical simulations and experimental tests. The first step will be a simulation using a finite elements software to establish the stress distribution in compressed masonry elements. The second stage corresponds to the experimental phase. The experiments will be performed in blocks (14x19x39 cm³), prisms with two and three blocks and masonry wallets. Furthermore, to investigate the influence of grout filling over the acoustoelastic effect, the experiments will be performed in empty and filled elements. The elements will be simultaneously subjected to uniaxial compression and to Ultrasonic Pulse Velocity (UPV) tests to determine the relative variation of propagation velocity as a function of the applied stress. The results will be analyzed through coda wave interferometry. The third step consists of a dynamic numerical simulation to evaluate the wave propagation in the masonry elements. It is expected that this research will contribute to a better understanding of the acoustoelasticity phenomenon. This work is part of the research area in non-destructive testing developed by Prof. Dr. Vladimir G. Haach in the Department of Structures of the São Carlos School of Engineering. (AU)