Reinforced Concrete T-beam Erosion-resistant Construct

The steel corrosion in concrete is the most important and direct factor for degradation of concrete structure durability. Towards the highway bridge concrete structure, affected by the atmospheric environment and deicing environmental, the steel corrosion phenomenon is very significant, which leads to cracking of concrete cover, shedding, seriously affecting the structural appearance and even endangering its safety.Aiming at the different environmental factors (atmospheric environment and deicer environment), different structural measures including concrete cover thickness, stirrup spacing, component section forms, and rusty retardant agent, have been study in this paper, which act on the main steel corrosion process in the bottom of the T-beam web. Through factor analysis, the sensitivity estimate of structural measures is found to improve the concrete structure durability. The result provides a reference for the design of concrete bridge structure. Design staff should attach importance to the durability design, select reasonable structure form, layout and structural measures, which can help to reduce the role of environmental factors on the construction.1. Using indoor artificial climate and environment case, indoor test method and test system have been designed, which can be simulated concrete specimens in atmospheric environment and deicer environment.2. In addition to the indoor simulating test of deicer environment, transport model of chloride erosion has been study under the conditions of dry-wet cycle, which belongs to the coupling relationship between chloride concentration diffusion and convection transport in the unsaturated porous state.3. Chloride distribution in concrete and steel corrosion rate test show that dripping eaves type affecting on the improvement of durability is optimum in all section forms of concrete T-beam web bottom, right-angle type is second, followed by round type. However, in atmospheric environment, the different section forms to improve structure durability are not obvious. Orthogonal analysis shows that the sequence of structural measures influence from big to small is rusty retardant agent content, cover thickness, section forms, which act on steel corrosion. When the steel corrosion rate is low (<1.5%), steel corrosion rate and chloride content around steel exist a good linear relationship.4. Using test and computer simulation, stirrup spacing affected on the concrete structure durability has been analyzed. The results indicate that along with the increase of concrete cover thickness, the maximum corrosion expansion force of concrete specimen increases; stirrups encryption can be reduced the maximum principal tensile stress of specimen surface, thus inhibited or delayed the appearance of corrosive cracks.