Numerical simulation of failure process of high-strength concrete using the discrete-element model

A two-dimensional mesoscopic model is presented for simulation of the failure process of high-strength concrete (HSC) confined by fibre-reinforced polymer (FRP). The model is based on the discrete-element method and modified rigid-body spring model, which were developed for simulation of the behaviour of normal-strength concrete, and is extended here to model HSC. Due to the fact that the mortar matrix and the interfacial layer in HSC are generally stronger than the strength of the aggregate, springs are designed in such a way that the crack can penetrate into the aggregate. To develop the confined model, FRP elements are connected to the basic model as rectangular elements, the connections of which are modelled together based on Hooke's law in cylindrical coordinates. Interfacial springs between FRP and concrete elements are designed based on the bond–slip model and the behaviour of concrete core under confining action provided by the FRP jacket. The failure behaviour of three unconfined and two confined HSC specimens was simulated by the proposed model. Analytical results are presented as stress–strain curves and crack modes, which were found to be in good agreement with experimental data.