Research On Impact Behavior Of RC Beams Due To Reinforcement Corrosion

Impact loads often cause significant damage to reinforced concrete(RC) structures, and then seriously affect the safety of the structures and endanger people’s lives and property. Under the impact loads, the material property, mechanical property and failure mode of RC structures are obviously different from the behaviors under static loads because of strain rate effect of materials and i nertial effect. Reinforcement corrosion often causes the degradation of RC structure property, and then serious affect the safety and applicability of RC structures. Bearing capacity reduction, failure mode change and bond capacity degradation caused by reinforcement corrosion are always serious dangers to the security of structures in marine environment, offshore environment and some special industrial environment. In impact-resistant property problem and durability degradation problem of RC structures, although there are a lot of research findings referring to one of the two problems, research that referring to structures s ubjected to both corrosion and impact loads at the same time is rare. So in this study, in order to investigate the degradation process of failure mode change, impact-resistant capacity and deformation with the development of reinforcement corrosion, the i mpact-resistant behaviors of RC beams subjected to steel corrosion are investigated experimentally. The main research contents of this thesis are summarized as follows:(1) Based on the data collection and statistical analysis of the existing experimental data referring to the bond between corrosion reinforcement and concrete, a model used to calculate bond strength is developed.(2) The accelerated corrosion process of steel reinforcement is studied and the principle of accelerated corrosion process, test equipment and the control of corrosion are introduced. The corrosion damage of the RC beams and the steel shape after corrosion are analyzed and discussed.(3) Based on the static experiment on 4 concrete beams with different corrosion levels, the degradation process of carrying capacity and deformation with the development of reinforcement corrosion is researched. The influence of reinforcement corrosion level, average corrosion-induced crack width and maximum corrosion-induced crack width on the shear be aring capacity of RC beams is obtained.(4) Falling-weight impact tests are conducted on 8 RC beams with different corrosion levels. Main attentions are paid to the influence of longitudinal reinforcement corrosion level and the impact velocity on the fail ure mode, the time histories of impact force, the time histories of reaction force and the energy dissipation. The degradation process of impact-resistant behaviors of RC beams with the development of reinforcement corrosion level is introduced.