Deterioration mechanism and uncertain life prediction of concrete under composite salt erosion
摘要
Aiming at the problem that the deterioration mechanism of concrete in composite salt environment is unclear and the service life is difficult to predict accurately, this study systematically carried out the deterioration law and life prediction under the combined erosion of bicarbonate, sulfate, and chloride. Through the mechanical and dynamic index test of 1~~13 months of age, the comprehensive damage index is constructed, and the Weibull model is used to describe its evolution law. Based on the non-parametric Monte Carlo resampling method of experimental data, the confidence interval and reliability estimation of damage degree are realized, and the uncertainty of life prediction is quantitatively characterized. Combined with multi-scale microscopic tests such as XRD and X-CT, the deterioration mechanism of concrete from early densification to crystal growth and decalcification under the action of composite salt was clarified, and the quantitative correlation between pore parameters and macroscopic damage was established. The multiple coupling of mechanism analysis, life prediction, and reliability evaluation was realized, which provided a new theoretical basis and method support for the durability prediction of concrete in complex service environment.