水泥-硅灰体系早期收缩与强度相关性  

Correlation of the autogenous shrinkage and the compressive strength of cement-silica fume blended pastes in early age

作　　者：邹迪[1] 肖莲珍[1] 李炳昊 任政 

机构地区：[1]武汉工程大学材料科学与工程学院,湖北武汉430073

出　　处：《混凝土》2017年第11期23-26,共4页Concrete

基　　金：武汉工程大学研究生创新基金(CX2015015);国家自然科学基金(51348001;51478200)

摘　　要：测试了20℃下,不同硅灰掺量(0、5%、10%、15%)在水胶比分别为0.40、0.50的水泥-硅灰水化体系中,7 d的自收缩及1、3、7、28 d的抗压强度。发现浆体的自收缩和抗压强度在早期均发展较快;水胶比越小,自收缩快速增长期越短,抗压强度越大。同一水胶比下样品每增加5%硅灰快速收缩时间提前1 h;当硅灰掺量为10%时,0.4水胶比下快速增长阶段的自收缩值占到7 d自收缩值的54.6%,0.5水胶比下的样品则占60%。空白样品7 d的抗压强度占到28 d的85.6~75.6%,10%硅灰样品7 d的抗压强度占到28 d的78.6%~69.1%,表明掺硅灰样品7 d前早期抗压强度发展较慢,主要是稀释作用占主导。0.4、0.5水胶比下10%硅灰样品28 d的抗压强度分别为空白样品的111.6%、123.0%,表明硅灰的掺入对于28 d水泥浆样品的后期抗压强度有一个提升作用,微集料填充和火山灰效应占主导。在水泥-硅灰水化体系中自收缩和抗压强度之间存在着良好的线性关系,研究成果可为实际工程中预测自收缩或抗压强度提供参考。The cement-silica fume blended pastes were prepared with different silica fume（SF）dosages of 0,5%,10%,and 15% at different water-binder ratios（W/B）of 0.4 and 0.5.The autogenous shrinkage（AS）and the compressive strength of the paste samples in the hydration period of 7 d（168 hours）were measured.It is found that the AS and the compressive strength of the paste samples were developed rapidly in the early period.The lower W/B,the shorter the rapid growth period,and the higher compressive strength was obtained.For the same W/B,each 5% increase of SF content,the rapid growth of the AS occurred by 1 h earlier.For sample P0.4 SF10,the proportion of the AS value in the rapid growth stage to that at 7 d is 54.6%.However,the corresponding proportion in sample P0.5 SF10 is 60%.The compressive strength at 28 d for sample P0.4 SF10 is 111.5% of the plain sample P0.4 SF0,indicating that SF has a promoting effect on the later compressive strength of the sample.There is a good linear relationship between the AS and compressive strength with the change of silica fume and W/B.The study results can provide reference for being predict the AS and compressive strength in practical engineering.

关 键 词：硅灰 自收缩 抗压强度 水胶比 

分 类 号：TU528.31[建筑科学—建筑技术科学]