The double-edge notched specimen (DENS) applied to study the fracture of concrete under shear loading: experimental approach

Abstract

The Double-Edge Notched Specimen (DENS) under compression loading has been recently proposed by Reinhardt to study the fracture of concrete under tangential stresses. The testing procedure was successful with highly orthotropic materials, but some doubts remain about its applicability to mortar and concrete, particularly to evaluate mode II fracture energy. This paper shows the experimental set up and measurements devoted to check the suitability of this testing procedure for analysing the fracture of concrete under shear loading (mode II). Tests were performed with concrete specimens (three sizes) and PolyMethylMethacrylate (PMMA). The paper presents the experimental details, especially the procedures to detect and follow the starting and growing of the cracks. The experimental records are also shown. The results show that the fracture of concrete starts under high tangential stresses (mode II), but, after this initial phase, the cracks grow under predominant tensile stresses (mode I).