Service Life Prediction of Concrete with Combined Air-Entraining Admixture and Fibers under Freeze–Thaw Cycles Based on Critical Water Saturation Theory

Abstract

Freeze-thaw resistance ability of concrete is an important issue when evaluating its durability. In this research, the objective was to predict concrete resistance to such cycles by analyzing water absorption based on the critical water saturation theory. In order to achieve this goal, detailed experiments were conducted, including water absorption, pore structure scanning, and mercury intrusion porosimetry of concrete with air-entraining admixture and different fiber content to obtain critical indicators, such as water absorption, porosity, and air void spacing factor, which formed the basis for predicting the service life of concrete. To predict the service life of concrete under freeze-thaw cycles, the critical saturation theory was utilized, taking into account environmental parameters and experimental indexes. The service life of concrete against freeze-thaw using air-entraining admixture and fibers had been calculated quantitatively in this paper. The results show that the predicted service life of concrete with air-entraining admixture was increased by more than 50 times, and using both air-entraining admixture and fiber could increase the service life by more than 80 times, even reaching 249 years.