On the potential of lattice type model for predicting shear capacity of reinforced concrete and SHCC structures

Abstract

Due to the brittle nature of shear failure, shear capacity is considered to be one of the most critical and relevant issues in the design of concrete structures. In this research, the possibility of using a discrete lattice model to predict the shear capacity of reinforced concrete beams is investigated. Beams without shear reinforcement and with different beam geometry and varying reinforcement ratios were studied and fracture behaviour from the simulations is compared to experimental results. Improving (shear) models is important to assess the remaining capacity of existing structures, but also to help design of strengthening solutions for structures with insufficient capacity. In this respect, numerous innovative concrete types have been developed offering possibilities to improve the flexural or shear capacity of concrete structures. Strain Hardening Cementitious Composite (SHCC) and Ultra High Performance Concrete (UHPC), obtained by implementing fibres in the cement based matrix, are such materials. Due to fibre addition and special micromechanical design, especially the ductility, but also the strength, of these materials is significantly improved compared to regular concrete. As a result, structural behaviour of reinforced SHCC and UHPC differs from that of regular concrete. In this research it is further investigated by lattice model analyses. Once the shear behaviour of conventional reinforced concrete and reinforced SHCC (or UHPC) can be reliably simulated, the lattice model might possibly also be suitable to investigate the capacity of concrete structures retrofitted by a layer of SHCC (or UHPC).