粉煤灰混凝土绝热温升的试验研究

目的 研究不同粉煤灰的掺量和不同水肢比条件下粉煤灰混凝土的绝热温升和胶凝材料水化速率的发展规律．方法 利用混凝土绝热温升仪测试混凝土绝热温升．结果 在水胶比0．53条件下，混凝土的绝热温升值随着粉煤灰掺量的增加而下降；在水胶比0．25条件下。绝热温升值先随着粉煤灰掺量的增加而增大，当掺量达40％以后绝热温升值开始下降。混凝土中胶凝材料的水化速率峰值随粉煤灰掺量增加而下降．结论 粉煤灰混凝土的绝热温升受水胶比和粉煤灰掺量共同影响，低水胶比条件下只有适当增加粉煤灰的掺量才能降低粉煤灰混凝土的绝热温升；高水胶比条件下。粉煤灰混凝土的绝热温升随粉煤灰掺量增加而下降。

Experimental Analysis of Adiabatic Temperature Rise of Fly Ash Concrete

The influences of dosage of fly ash on the adiabatic temperature rise and the hydration rate of concrete are investigated.Adiabatic temperature rise is measured by concrete adiabatic temperature measuring device.For water binder ratio 0.53 with lower strength grade concrete,the adiabatic temperature rises of concrete decrease when dosage of fly ash increases.For water binder ratio 0.25 with high strength grade concrete,the adiabatic temperature rises of concrete increase when the dosage of fly ash increases.However,when the dosage is and over 40%,it decreases.The peak value of binder hydration rate decreases when the dosage of fly ash increases.The adiabatic temperature rise of fly ash concrete is influenced by dosage of fly ash and water binder ratio.The adding rate of fly ash in the binder could be higher in low water ratio concrete than that in high water ratio concrete for controlling concrete temperature rise.