多因素耦合作用下水工混凝土性能变化规律及寿命预测研究OA

The degradation mechanism and service life prediction of hydraulic concrete subjected to coupled freeze-thaw cycles,chloride attack,and sulfate erosion remain insufficiently understood,and reliable predictive models are still lacking.Taking a regulating sluice project as the engineering background,this study investigates the evolution of mass loss,compressive strength,and dynamic elastic modulus of hydraulic concrete with water-binder ratios of 0.40,0.50,and 0.60 through 300 laboratory freeze-thaw-erosion coupling tests.An exponential decay model was employed to analyze the deterioration characteristics of concrete performance.The results indicate that concrete degradation follows a three-stage evolution pattern,and a lower water-binder ratio significantly delays damage development.The modified exponential decay model exhibits high fitting accuracy,with coefficients of determination(R2)not less than 0.984,among which the dynamic elastic modulus is identified as the most sensitive damage indicator.Based on these findings,a dual-control service life prediction model was established,yielding a predicted service life of 39.3 years for the secondary reinforced concrete structure of the project.The proposed model and results provide a scientific basis for durability design and life assessment of hydraulic concrete in cold,arid,and saline environments.