Abstract:Compared with original rock wool(ORW), the durability of the rock wool board fiber(RWBF) used in Portland cement based materials was analyzed. After accelerated corrosion for 28d in cement filtrate, the concentration of the chemical elements in the corroded solution, the micro morphology of the fibers, the distribution of surface chemical elements and the mineral composition were tested. It is found that after accelerated corrosion for 28d, the ORW turns totally to powder, while the RWBF maintains good fiber shape; dissolution rate of silicon and aluminum in the RWBF was significantly lower than that of the ORW and milled powder. During the accelerated corrosion process, the main product was hydrated calcium silicate, and RWBF generates the minimum amount. Due to the adhesive and water repellent on its surface, RWBF has certain protective effect and much higher corrosion resistance than ORW.