Effect of different boundary conditions in direct tensile tests: experimental results

Abstract

The effects of the kinematic ‘constrained’ of a direct tensile test on the complete load—displacement response in tension of concrete specimens were examined from tests with imposed uniform displacement (fixed platens) and from experiments with free rotation rotating platens through a closed-loop testing system. Cylindrical specimens and prismatic specimens were considered. The tests were monitored with an interferometric strain measurement (electronic speckle pattern interferometry). A notable outcome of the experiments is that the fixed platens imposed a more uniform strain field with higher peak loads. Also the post peak branch had a shape that depends on the boundary conditions under which the tests were performerd.