Probabilistic quantitative analysis on the contents of sulfate corrosion products in concrete

Abstract

A probabilistic quantitative method is proposed in this paper to depict the random evolution process of the contents of sulfate corrosion products (CSCP) in concrete. The method includes the stochastic kinetic equation established according to sulfate corrosion reactions leading to formation of corrosion products, and probability description of the CSCP. The stochastic kinetic equation is presented based on the chemical Langevin equation for complex reactions (CLE-CR), in which internal fluctuations are regarded as white Gaussian noises. Sulfate corrosion reactions are assumed to occur in a well-stirred system without considering diffusion effects of ions. The probability distribution of the CSCP can be obtained by using the statistic approach to analyze the computation results of the stochastic kinetic equation. The model is validated by the experiments performed in the study and in the literature respectively. The results show that the CSCP in concrete at each time step should be treated as a random variable following a certain probability distribution. The discreteness of experimental results can be quantitatively described by the coefficient of variations (CVs) of random variables. The probabilities of experimental results attained by the proposed method can be employed to judge the reliability of data. Furthermore, in order to evaluate the effects of the CSCP on concrete durability, the model can also be used to predict the developing trends of the CSCP, as well as providing their probabilistic information.