Exploring durability and environmental impact of cementitious composites modified by fluoroalkyl-silane based additive

This article focuses on an original molecular pathway to predict the durability and analyze the environmental impact of fluoroalkyl-silane (FS) based additive modified cementitious composites in marine environment. The key is to reveal the calcium leaching behaviors of cement composites through molecular simulation, then evaluate the porosity and chloride diffusion coefficient, which determines their lifespan. Simulation results indicate that decalcification can be eliminated through FS surface modification, decreasing the porosity, and slowing down chloride accumulation. Then we map the simulation findings to their environmental impact by quantitatively analyzing the lifespan of a cement cover in marine environment. It is demonstrated that 0.762 wt% FS is the optimal mixing content, which significantly reduces the repair frequencies. In such a condition, 52.33 % CO2 emissions and 31.07% non-renewable energy consumption can be diminished. Our findings portray an atomic understanding for improving the durability of cement composites and propose strategies to predict their service life and environmental impact. © 2023 Elsevier Ltd