粉煤灰粒度分布对低温水泥砂浆孔结构特征的影响

Impacts of particle size distribution of fly ash on characteristics of pore structure of low temperature cement mortar

为了降低混凝土结构冬季施工成本及有效利用粉煤灰,研究在不同养护条件下粉煤灰粒度分布对水泥砂浆孔结构特征的影响,通过将原状粉煤灰筛分为不同粒度区间并测得每个区间百分率,使其满足S.Tsivilis分布,采用可蒸发水含量法和压汞法测试恒负温和自然变低温养护条件下粉煤灰粒度分布对水泥砂浆孔隙率及孔径分布情况并进行SEM微观分析。结果表明:不同粉煤灰粒度分布对水泥砂浆强度及孔结构特征起改善作用,相较恒负温养护,冬季施工更适合自然变低温养护。

In order to reduce the construction cost of concrete structure in winter and utilize fly ash effectively,this study researches about the effects of particle size distribution of fly ash on characteristics of pore structure of cement mortar under different curing conditions,the fly ash is sifted into different particle size range by standard sieve,measuring the mass percentage of each particle size range in the total fly ash to satisfy the S.Tsivilis distribution and using the loss percentage of water(content of evaporative water)and mercury intrusion porosimetry(MIP)test the pore porosity and pore size distribution of cement mortar under the curing condition of constant low temperature and low temperature naturally varying,then microscopic analysis by SEM.The result shows different particle size distribution of fly ash improves the strength and characteristics of pore structure of cement mortar,the most appropriate curing method for the cement mortar used in winter construction is the curing method of low temperature naturally varying.