Abstract:
The effect of liquid accelerator on the durability of sprayed concrete was studied. The results show that low-alkaline liquid accelerator distinctly increases the shrinkage of sprayed concrete and decreases the frost resistance and permeability resistance of sprayed concrete. Alkaline-free setting accelerator has little effect on the durability of sprayed concrete. Also, the SEM and pore structure analysis show that low-alkaline liquid setting accelerator makes the hydration product of cement paste loose, increases the content of deleterious pores in cement paste. Alkaline-free setting accelerator promotes the formation of network in the paste and has no distinct effect on pore structure.