粉煤灰火山灰反应性及其反应动力学

POZZOLANIC REACTIVITY AND REACTION KINETICS OF FLY ASH

通过酸溶法测定了粉煤灰Ca(OH)2H2O系统中粉煤灰的反应率,以此来评估不同品质低钙粉煤灰的火山灰反应性,并据此建立了低钙粉煤灰火山灰反应的动力学模型。探讨了不同品质粉煤灰火山灰活性上的差异对水泥基材料强度的影响。结果表明:相比于Ⅱ级粉煤灰,Ⅰ级粉煤灰的火山灰活性未必更高。粉煤灰的火山灰反应符合一级反应动力学模型。不同品质粉煤灰火山灰活性上的差异宏观上对水泥砂浆强度影响甚微。

Reaction ratio of fly ash in fly ash-Ca(OH)2-H2O 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.