Silica fume effect on fracture parameters and cracking pattern maps of recycled aggregate concrete

Abstract

The paper demonstrates the determination of the fracture parameters of concretes included recycled aggregate (RA) and silica fume (SF) and the crack pattern of a reinforced concrete beam. Double-K fracture model (DKFM) is considered in this paper and the required parameters for DKFM are obtained from the model simulated using finite element method (FEM) in Abaqus. In the simulation parts geometric nonlinearity and material nonlinearity is considered and the parameters of materials for modelling applications depends on the experiments. The fracture parameters are calculated after obtaining the FEM model analyses. The implemented study of fracture behavior of the conventional and recycled aggregate concretes with and without SF and RA reveals that the conventional concrete fracture models (double-K fracture model) could be used to determine the fracture parameters and fracture behavior of RAC and both SF and RA use in concrete has an effect on fracture properties is found. Moreover, crack pattern of a reinforced concrete beam with and without RA and SF is investigated. According to the results, number of cracks decrease but the depth of cracks increase and initial cracking toughness increases if both RA and SF are used at various ratios in the concretes. Although RA inclusion in concretes decreases the rigidity of the beam, approximately equal elastic bearing capacity of the beam is found.