流变参数对自密实混凝土等效砂浆静态稳定性的影响  

Influence of Rheological Parameters on Static Stability of Self-Compacting Concrete Equivalent Mortar

作　　者：马昆林[1] 冯金[1] 龙广成[1] 谢友均[1] 陈小波[1] 

机构地区：[1]中南大学土木工程学院,高速铁路建造技术国家工程实验室,重载铁路工程结构教育部重点实验室,长沙410075

出　　处：《硅酸盐学报》2017年第2期196-205,共10页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(51678569,51678568);国家“973”计划(2013CB036201);中南大学教师科学基金(2014JSJJ013)资助

摘　　要：采用旋转黏度计测试了基于混凝土等效砂浆法所配制砂浆的塑性黏度和触变性,采用冲模–揭板试验研究了不同塑性黏度和触变性的砂浆硬化后表面的气泡特点,采用硬化后砂浆表层气泡率和表层气泡直径对砂浆的静态稳定性进行了表征。结果表明:塑性黏度和触变性对硬化后砂浆表层气泡率和直径均有重要影响。相对于触变性,塑性黏度与砂浆表层气泡率和直径的相关性更高。砂浆表层气泡率和气泡直径均随黏度增大而显著减少,砂浆黏度不低于3.5 Pa·s时,表层气泡率小于5%,直径大于5 mm的气泡数量接近零。砂浆表层气泡率随触变性增加而减少,砂浆触变性不低于12.5×10~3 Pa/s时,砂浆表层气泡率基本小于10%。当砂浆塑性黏度不低于3.5 Pa·s且触变性不低于12.5×10~3 Pa/s时,其静态稳定性较好。The plastic viscosity and thixotropy of self-compacting concrete equivalent mortar （SCCEM） were tested by rotational viscometer. The surface bubbles characteristics of mortar with different plastic viscosities and thixotropies were investigated by a self-designed filling-box device. Two parameters of surface bubbles ratio （SBR） and surface bubble diameter （SBD） of hardened mortar were used to characterize the static stability of mortar. The results show that the plastic viscosity and thixotropy both have great influences on SBR and SBD. Compared to the thixotropy, the correlation between the plastic viscosity and SBR/SBD is better. SBR and SBD of mortar decrease dramatically with the increasing plastic viscosity. When plastic viscosity is no less than 3.5 Pa＇s, SBR is less than 5% and SBD larger than 5 mm is close to zero. SBR of mortar reduces with the increasing thixotropy. SBR is almost less than 10% when the thixotropy of fresh mortar is more than 12.5 × 10^3 Pa/s. When the plastic viscosity is more than 3.5 Pa.s and the thixotropy of fresh mortar is more than 12.5× 10^3 Pa/s, SCCEM has a good static stability.

关 键 词：自密实混凝土 混凝土等效砂浆 塑性黏度 触变性 静态稳定性 

分 类 号：TU528[建筑科学—建筑技术科学]