Study on the accelerated corrosion testing of cement-based grouts

The accelerated corrosion testing method (ACTM) for grouts is described in this paper, and has been used to test the corrosion resistance of three kinds of grouts (plain, with fly ash, with silica fume). The chloride diffusion coefficient of the grouts has also been measured at different ages. With the Fick's second law and the relation between chloride diffusion coefficient and time, the mathematical relation between time-to-rapid corrosion and grout thickness is deduced. By comparison with the recursive relation of test results, it indicates that the diffusion rule of chloride ion has not been changed by accelerated corrosion testing method, which only accelerates the diffusion rate of chloride ion in the grout. The results also show that fly ash or silica fume can remarkably improve the chloride ion resistance of grouts (the increase in time-to-rapid corrosion is of 50% and 90% at early age, respectively with the addition of fly ash and silica fume and more than 150% at latter age) and that ACTM can be available for measuring the durability of grouts.