Experimental study of dynamic material properties of clay brick and mortar at different strain rates

It is well known that most construction materials behave differently under highspeed and static loading conditions. The strain rate effect on many materials, such as metals, concrete and rock, has been intensively investigated. However, the strain rate effect on masonry materials, such as clay bricks and mortar mixed with cement, lime and sand, cannot be found in open literature. Understanding the strain rate effects on masonry materials is important for accurately modelling masonry structure damage to high-velocity impact and blast loads. This paper reports experimental results of the strain rate effect on clay bricks and mortar materials. Uniaxial compression tests were carried out on brick and mortar specimens at various strain rates ranging from quasi-static (10-6/s) to dynamic up to a strain rate of 200 /s. The strain rate effect on the yield and ultimate strength, yield and ultimate strain, elastic modulus, and Poisson's ratio of clay brick and mortar material are determined from the testing results. Empirical relations of dynamic increase factors (DIF) for the material properties are derived and presented. Discussions and comparisons of the DIF of brick and mortar obtained in this study are also made with other geomaterials, such as concrete and rock.