Performance Of Stainless-carbon Steel Bars Reinforced Concrete Structure

Reinforced concrete structure is a widely-used structure in civil engineering, and steel corrosion is one of the main causes for durability issues of reinforced concrete(RC) structures. Stainless steel is expected to be an excellent substitute material for traditional carbon steel, however its initial cost is much higher. To satisfy both requirements of durability and economy, using stainless steel bars together with carbon steel bars as reinforcements in concrete is an effective way. However, little is known on the performance of stainless steel and carbon steel bars reinforced concrete structures.Therefore, the material corrosion characteristics of carbon steel coupled with stainless steel and the mechanical performance of stainless steel and carbon steel bars reinforced concrete structures were carried out in this article. The main research contents include:(1) To determine the adverse effect of galvanic corrosion on the steels, carbon steels coupled with stainless steels were tested in the concrete simulated pore solution containing chloride ions. Linear polarization (LPR) and zero resistance current (ZRA)methods were adopted to measure the corrosion current and the galvanic corrosion current to reflect the corrosion rates of carbon steel. The test result show that the corrosion rate of carbon steel is accelerated by the effect of stainless steel.(2) To identify the flexural behavior of concrete beams reinforced with carbon steel bars and stainless steel bars, the tensile tests of steel bars were first carried out to obtain their mechanical characteristics. Then the flexural properties of stainless steel and carbon steel bars reinforced concrete beams were tested. The average width, the maximum crack width, the mid-span deflections of the beams under the limit state with different reinforcement conditions are compared, and the reasons for the differences are analyzed. The test result show that the method given in the design code of concrete structure can be used to predict the average crack width and the maximum crack width,however it should be modified with k? to calculate the deflection of stainless steel reinforced concrete structure.(3) On the basis of the experimental results and the relating constitutive relations,a reasonable constitutive model such as Rasmussen model was reached. Then,an improved design method for bending of stainless steel reinforced concrete is put forward. The calculation results agree well with the test value, which validates the new model gotten in this article.