Tensile strength of clay blocks: An experimental study

Direct tensile tests were performed on two series of hollow clay block masonry units. The blocks were subjected to tension in two orthogonal directions, which were perpendicular to the extrusion direction. For these tests a special test procedure was developed. The present paper describes this procedure in detail and discusses the obtained results. All specimens failed in a brittle manner and their tensile strength exhibited a relatively large scatter. The possible causes of this scatter are discussed. Further, the test results are statistically analysed. As a result of this analysis it is recommended to apply log-normal distribution for the representation of the net tensile strength of hollow clay blocks.

► Direct tensile tests were performed on two series of hollow clay block masonry units.
► The clay blocks behaved linear-elastically up to brittle failure.
► Test data exhibited relatively large scatter, mostly due to initial cracking of units.
► The ratio of net tensile to compressive strength of the block was 4%.
► The log-normal distribution is recommended for representing of the tensile strength.