Frost resistance of internal curing concrete with calcined natural zeolite particles

Abstract

In this paper, the frost resistance of internal curing concrete with calcined zeolite particles was studied, comparing with ordinary curing concretes. Concrete specimens with compressive strength of 50 MPa and 100 MPa were prepared. Firstly, the pore structure characteristics of the concrete specimens were tested by mercury intrusion porosimetry. Then freeze–thaw test was conducted, residual deformation, weight loss and strength loss of concrete specimens during freeze–thaw cycles were measured to investigate the frost resistance of the specimens, and water saturation degree of the specimens during freeze–thaw cycles was tested to analyze the mechanism of frost resistance. Results show that, the porosity and pore structure of concrete can be improved by prewetted zeolite particles with the development of curing age. For the same water absorption time, the water saturation of zeolite curing concrete is higher than that of ordinary curing concrete in the initial stage of freeze–thaw cycles, but the growth rate with the development of freeze thaw cycles is much slower. The frost resistance of concrete using calcined zeolite is slightly worse than that of ordinary curing concrete in early stage of freeze–thaw cycles, while it is much better in the middle and later stage.