Impact Of New Composite Inhibitor On The Corrosion Resistance Performance Of Reinforced Concrete

The durability of the reinforced concrete structure is one of the most concernedproblems in the construction industry, and indirectly affects the sustainabledevelopment of the state and society. As one of the major problems resulting in thedurability degradation of reinforced concrete structure, the corrosion of reinforcementhas caused a big waste of state economy. Therefore, research on measures to inhibitreinforcement corrosion and corresponding materials is particularly important. Studiesshow that corrosion inhibitors is the most effective way to prevent steel corrosion, andhas been investigated and developed for a long time, especially the environmentfriendly one. However, most studies about corrosion inhibitors focus on being used inthe simulated concrete pore solution, rather than in the real concrete situation, and thereal-time monitoring electrochemical parameters of reinforcement corrosion situation isquiet less.The purpose of this subject is to develop a new kind of composite corrosioninhibitor and further discuss its performance and anticorrosion effectiveness insimulated pore solution and concrete respectively. Firstly, the N, N-dimethylethanolamine (DMEA) was chosen as the corrosion inhibitor to make sure the optimalcontent in the simulated concrete pore solution through the electrical parametersmeasured by the electrochemical method. Then changing the amount of sodiummonofluoropHospHate (MFP) based on the fixed optimal amount of DMEA can get theratio of two corrosion inhibitors under the same method in order to achieve the bestanticorrosion effectiveness. Secondly, the critical content of chloride ion in thesimulated pore solution under the above optimal ratio and the comparison ofanticorrosion effectiveness of composite inhibitors and commercial corrosion inhibitors,including NaNO2and SiKa901, were studied respectively. The results manifest that theanticorrosion effectiveness of developed composite inhibitor was obvious when massfraction of sodium chloride incorporated into concrete was within3%and4%andsuperior to NaNO2and SiKa901with3.5%sodium chloride.The corrosion inhibitor was incorporated into the concrete with the optimal ratio ofDMEA and MFP to monitor the variation in electrochemical parameters of steelreinforcement in concrete, such as self-corrosion potential, polarization resistance andAC impedance spectroscopy. Comparison of influence of composite inhibitor and single inhibitor on corrosion resistance with different contents was done to evaluate utility ofthe DMEA and MFP. Besides, the effect of water to cement ratio as well as mineraladmixture on the reinforcement condition under the fixed amount of compositeinhibitors was also studied. Moreover, the equivalent circuit was built byelectrochemical fitting software and comparison of measured values and fitting onesthrough which we analyzed the overall features of AC impedance spectroscopy. Thestudy shows that: different water to cement ratios have a great influence on theanticorrosion effectiveness of composite inhibitors which in low W/C is better than inhigh one.Finally, research on reinforcement resistance to chloride ion in concrete includingcorrosion inhibitor was done, under the impact of the carbonization and the couplingaction between carbonization and electrical accelerating chloride salt. We can concludethat incorporation the developed composite inhibitors can improve the reinforcementresistance to carbonization for7d and14d carbonation test; Under the effect of coupling,concrete structure mixed with composite inhibitors has preferable corrosion resistanceto that mixed with Sika901.