Specific fracture energy for normal strength concrete, high strength concrete and fibre reinforced concrete - three approaches

Abstract

For the analysis of cracked concrete structures, advanced mechanical properties, such as fracture energy and the corresponding tension softening relation are essential. Although significant studies have been reported on evaluation of specific fracture energy, still, there is no clarity and applicability of the approach for various concretes. This paper examines the determination of fracture energy by using (i) RILEM work of fracture with tail correction to loaddisplacement plot (ii) boundary effect model of Hu and Wittmann and (iii) energy release rate approach for various concrete mixes. Several concrete mixes, whose compressive strength ranges from about 20 to 90 MPa comprising of normal strength concrete, high strength concrete and fibre reinforced concrete have been considered in the present study to evaluate the specific fracture energy. From the study, it is observed that the specific fracture energy obtained by the above methods are in close agreement with each other and designer can employ either of the methods for analysis and design of concrete structures and also for safety evaluation of sensitive structures.