Mechanical properties, permeability and durability of accelerated shotcrete

• Compressive and splitting tensile strength regression equation of shotcrete was established.
• Durability of ordinary concrete, shotcrete with and without steel fiber for the same mixture was tested.
• Compared with ordinary concrete, shotcrete had better durability except to chloride ions.
• Steel fiber can obviously improve the durability of shotcrete.
• Microstructure of specimens after erosion were characterized by using XRD, TG-DSC and SEM.

In this paper, the experiment is completed into two phases. In the first phase, the performance of setting time of pastes, mechanical properties of shotcrete at different hydration age and permeability of shotcrete at 90 day were tested. Meanwhile, in the second phase, the durability performance of shotcrete with 10% fly ash and 0.64 vt.% steel fiber was studied under environment corrosion which included freeze–thaw cycle, accelerated carbonation test with and without bending load, sulfate attack, chloride ion diffusion and acid corrosion respectively. The results showed that, in comparison to ordinary concrete (OC) with the same mixture, ordinary shotcrete (OS) had better durability properties except to chloride ion. Thus, steel fiber (steel fiber reinforced shotcrete, SFRS) not only led to much denser microstructure in shotcrete matrix but also could significantly improve the early-age compressive and splitting tensile strength, permeability and durability of shotcrete.