磷渣粉替代粉煤灰对外掺MgO碾压混凝土性能的影响  

Effect of phosphorus slag powder replacing fly ash on performance of MgO-admixed RCC

作　　者：陈荣妃[1] 陈昌礼[1] 杨华山[1] 赵振华[1] 刘小萤[1] CHEN Rongfei;CHEN Changli;YANG Huashan;ZHAO Zhenhua;LIU Xiaoying(School of Materials and Architectural Engineering,Guizhou Normal University,Guiyang 550025,China)

机构地区：[1]贵州师范大学材料与建筑工程学院,贵州贵阳550025

出　　处：《水利水电科技进展》2022年第5期102-107,共6页Advances in Science and Technology of Water Resources

基　　金：国家自然科学基金(51869005);贵州省科技计划项目(黔科合平台人才[2018]5769-25)。

摘　　要：为寻求碾压混凝土中粉煤灰的替代掺合料,使用贵州磷渣粉部分或全部替代粉煤灰制备外掺MgO碾压混凝土,研究了采用不同掺合料的外掺MgO碾压混凝土的自生体积变形和力学性能,并采用X射线衍射、差热-热重分析、背散射电子成像、能谱分析、压汞分析等方法研究碾压混凝土的微观结构。结果表明:与单掺粉煤灰碾压混凝土比较,复掺磷渣粉和粉煤灰碾压混凝土的自生体积变形值变大,且随着磷渣粉掺量的增大而减小,而单掺磷渣粉碾压混凝土的自生体积变形值变小;在相同条件下,磷渣粉比粉煤灰对混凝土中MgO水化膨胀的抑制作用更强;用磷渣粉替代粉煤灰配制的碾压混凝土的孔隙结构得到优化,力学性能更高,且MgO水化产生的膨胀不会对其微观结构造成破坏;磷渣粉适宜替代粉煤灰配制外掺MgO碾压混凝土。In order to find an alternative admixture of fly ash in roller compacted concrete(RCC),Guizhou phosphate slag powder was used to partially or completely replace fly ash to prepare RCC mixed with MgO.The autogenous volume deformation and mechanical properties of MgO-admixed RCC,as well as the microstructure was investigated by means of X-ray diffraction,differential scanning calorimetry and thermogravimetry analysis,backscattered electron imaging,energy dispersive spectrum analysis,mercury injection porosimetry and so on.The results show that compared with singly-doped fly ash RCC,the autogenous volume change of RCC with phosphorus slag powder and fly ash becomes larger,and decreases with the amount of phosphorus slag powder,while the autogenous volume change of singly-doped phosphorus slag powder RCC is smaller.With the same conditions,the inhibitory effect of phosphorus slag powder on MgO hydration expansion of concrete is stronger than fly ash.The pore structure of RCC prepared with phosphorus slag powder replacing fly ash is optimized with better mechanical properties.The microstructure of MgO-admixed RCC cannot be damaged by expansion due to MgO hydration.Phosphorus slag powder is suitable to replace fly ash to prepare MgO-admixed RCC.

关 键 词：磷渣粉 粉煤灰 自生体积变形 外掺MgO碾压混凝土 微观结构 

分 类 号：TV431[水利工程—水工结构工程]