Initial cracking time of magnesium oxychloride cement reinforced concrete based on time-varying model of reinforcement corrosion

Affiliation of Author(s):航空学院

Journal:Dongnan Daxue Xuebao

Abstract:Aiming at the problem of high chloride content in magnesium oxychloride cement concrete, a time-varying model for the corrosion rate of steel in magnesium oxychloride cement concrete was studied by an electrochemical test. Combined with the corrosion current density and the theoretical model, the initial corrosion time of steel in magnesium oxychloride cement concrete and the cracking time of concrete were predicted. The results show that the corrosion rate of exposed steel (S1) is in agreement with the power function time-varying model: the corrosion rates of BNC® coated steel (S2), Zintek coated steel (S3), Dacromet coated steel (S4) and Geomet coated steel (S5) are all in line with the logarithmic time-varying model, and corrosion rate of Magni coated steel (S6)accords with exponential time-varying model. It is feasible to use the limit of the corrosion current density of steel as a standard for calculating the initial corrosion time of rebar in magnesium chloride cement concrete. S1, S2, S4 and S6 were corroded at the beginning of the test, and the initial corrosion time of S3 is 1 115 d and the initial corrosion time of S5 is 2 760 d. Compared with S1, the cracking time of S2, S3, S4, S5 and S6 is delayed by 345, 2 127, 192, 3 745 and 1 877 d, respectively. The feasibility, the long-term stability and the effectiveness of the coated steel bar in the magnesium oxychloride cement concrete are verified. © 2018, Editorial Department of Journal of Southeast University. All right reserved.

ISSN No.:1001-0505

Translation or Not:no

Date of Publication:2018-05-20

Co-author:Gong, Wei,Qiao, Hongxia,mhy,Chen, Guangfeng

Correspondence Author:Gong, Wei,yhf

Date of Publication:2018-05-20