POZZOLANIC REACTIVITY AND REACTION KINETICS OF FLY ASH

Reaction ratio of fly ash in fly ashCa(OH)_(2)H_(2)O system was measured by acid dissolution method, which was used for evaluation of pozzolanic reactivity of low-limed fly ashes. On this basis, the kinetics model of pozzolanic reaction of low-limed fly ashes was established.Effect of differences in pozzolanic reactivity among low-limed fly ashes on strength of cement mortar was investigated. Results show that the pozzolanic reactivity of grade Ⅰ fly ashes is not certainly higher than that of grade Ⅱ fly ashes. The pozzolanic reaction of low-limed fly ashes conforms with the class I kinetics model, and the differences in pozzolanic reactivity among low-limed fly ashes have little effect on the strength of cement mortar.