Mesoscopic simulation on flexural behavior of single-way reinforced concrete slab with rebars subjected to localized corrosion

Corrosion reduces cross-section area of rebar and bond between the rebar and concrete, which leads to the degradation of durability of structure. In this study, a three-dimensional mesoscopic numerical analysis model was established to explore influence of localized corrosion on behavior of single-way RC slab. In the model, concrete was considered as a tri-phase composite consisted of coarse aggregate particles, mortar matrix and interface transition zones (ITZs). The effect of corrosion was simulated by reducing cross-section area of rebar and bond. Localized corrosion of reinforcement was taken into account and non-linear spring element was adopted to describe interaction between concrete and reinforcement. The simulation results for corrosion RC slab are in good agreement with test result in terms of ultimate flexural capacity and displacement. On this basis, the flexural behavior of corroded single-way RC slab under fourth-point bending condition was simulated and analyzed whilst the influence of corrosion level, concrete strength, rebar type and diameter was investigated. Simulation results indicate that flexural bearing capacity of corroded RC slab increases when reinforcement was minor corroded and decreases for a further increasing corrosion level. The effect of concrete strength on bearing capacity of slab is insignificant with the increase of corrosion level. The RC slabs with plain rebar break in brittle failure when corrosion level is over 7.5%. However, slab with deformed rebar fail in a ductile pattern in this case. Under fourth-point bending condition, energy dissipation of RC slabs with larger reinforcement ratio decreases faster. The influence of reinforcement ratio and bond at rebar-concrete interface caused by the variation of rebar diameter is still significant when the rebar is corroded.