Abstract:In order to solve the corrosion problem of concrete reinforcement under harsh environment, six new corrosion inhibitors ZS1—ZS6 were synthesized by condensation of 1,4-phenylene diisocyanate or 1,4-phenylene diisothiocyanate and compound (I). The orthogonal experimental method was used to optimize the synthesis process conditions; The corrosion resistance performance of ZS1-ZS6 was tested by linear polarization and AC impedance method, and the optimal corrosion inhibitor was selected; The influence of corrosion inhibitor on the performance of concrete was tested according to the national standard method, and weight loss rate and corrosion inhibition rate of steel bars were tested under different NaCl concentrations according to ASTM G31-72(2004) method. The results show that the optimum preparation conditions of ZS1-ZS6 are as follows: the reaction temperature of 130 ℃, the molar ratio of 1∶1.3 between 1,4-phenylene diisocyanate and diethylene triamine, and the reaction time of 24 hours; Under the optimum conditions, the yield of ZS1-ZS6 reaches 95.7%~97.2%; ZS1-ZS6 all have good anti-rust performance, with ZS5 being the best. The Cl-diffusion coefficient and carbonization depth of the benchmark concrete specimens doped with ZS5 are greatly reduced, and the compressive strength, flexion strength and slump of concrete have little change before and after mixing with ZS5, indicating good compatibility with the concrete, which is beneficial for construction. After soaking carbon steel in a 3.5% NaCl corrosion medium containing ZS5 for 90 days, the radius of the bulk resistance curve still has an increasing trend, the weight loss rate of steel bars is low, the corrosion inhibition rate is high, and the rust resistance durability is good. ZS5 can effectively prevent the corrosion of concrete reinforcement, significantly improve the durability of concrete, and can be widely used in the construction of buildings in corrosive environment.