Material property for masonry design: correlating non-destructive and destructive tests

Abstract

Material properties for masonry design are characterized using two different methods, namely destructive test (DT) and non-destructive test (NDT). Destructive test is used to characterize the compressive strength of masonry, mortar and brick, and the modulus of elasticity of masonry while the non-destructive test is used to characterize only the modulus of elasticity of masonry. In the absence of test setups/for quick determination, the properties can be determined by using empirical equations. Idealization of stress-strain curves and different correlations for design parameters between the properties are proposed. Stress-strain curves are determined using DT and idealized into four categories (Type A to Type D) based on the post cracking stiffness ratio. Compressive strength of masonry is correlated with compressive strength of brick and mortar. Modulus of elasticity of masonry has been estimated using compressive strength of masonry as an input. Since the modulus of elasticity of masonry depends upon the constituent materials therefore modulus of elasticity is also correlated with compressive strengths of brick and mortar (in absence of modulus of elasticity) using linear regression. The modulus of elasticity which is one of the most important property in the design, requires specific test setup (strain measuring equipment etc.) for estimation. Therefore, an alternative solution, namely, non-destructive test can also be applied which can be comparable with DT. Modulus of elasticity of masonry is determined through NDT by comparing the natural frequency experimentally and analytically. Modulus of elasticity computed using DT and NDT are compared.