Modeling the Hydration of Cement Blended with Rice Husk Ash

摘要

A model of the hydration of cement blended with rice husk ash (RHA) is proposed in this paper. This model is a modification of the basic HYMOSTRUC3D model which was developed by Breugel (1991), Koenders (1997) and Ye (2003). The effects of RHA on the degree of pozzolanic reaction of RHA, the volume fraction of hydration products, the capillary- and the gel- porosity of cement paste can be obtained from this model. By using an appropriate amount of RHA replacement, the microstructure of RHA blended cement paste is improved, in which the pozzolanic reaction of RHA causes a decrease of Ca(OH)_2 content and an increase of CSH content of system. Some properties of RHA such as the particle size, the amorphous phase content and the replacement content were also evaluated in this model. The simulation results show that the pozzolanic activity of RHA is higher with the finer RHA or with the RHA containing a higher amorphous phase content. There is an optimum RHA replacement and the excess RHA has no contribution to the pozzolanic reaction between RHA and CH produced from cement hydration.