矿物质降黏剂对再生骨料混凝土流变、力学与耐久性能的影响  

Effect of Mineral Viscosity Reducer on Rheological,Mechanical Properties and Durability of Recycled Aggregate Concrete

作　　者：黄亮[1] 李北星[1] 杨宇程 田沈华 HUANG Liang;LI Beixing;YANG Yucheng;TIAN Shenhua(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China)

机构地区：[1]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070

出　　处：《硅酸盐通报》2025年第4期1458-1467,共10页Bulletin of the Chinese Ceramic Society

基　　金：国家重点研发计划(2020YFC1909904)。

摘　　要：为了改善再生骨料混凝土(RAC)的工作性能,研究了自制矿物质降黏剂(VR)掺量(等质量取代水泥8%、10%和12%)对RAC流变性能、强度、耐久性能和收缩性能的影响,并使用扫描电子显微镜对RAC微结构进行了分析。结果表明,随着VR掺量的增加,RAC的流变性能得到改善。当VR掺量为12%时,净浆黏度降低了32.8%,砂浆屈服应力和塑性黏度分别下降了42.0%和17.9%,坍落度和扩展度分别增大了50、40 mm,倒置坍落度筒排空时间缩短了65.7%。同时,VR的掺入使RAC的浆体和界面过渡区微结构变得致密,对RAC的强度和耐久性能具有良好的改善作用。当VR掺量为10%时,改善效果最佳,此时RAC的28 d抗压强度与劈拉强度分别增加了7.6%和17.2%,吸水率降低了22.6%,电通量和碳化系数分别降低了47.9%和29.9%。另外,VR轻微降低了RAC的干缩,但会在一定程度上增加RAC早期自收缩。In order to improve the working properties of recycled aggregate concrete(RAC),the effects of the amounts of homemade mineral viscosity reducer(VR)(8%,10%and 12%of cement replaced by equal mass)on the rheological properties,strength,durability and shrinkage properties of RAC were investigated.The microstructure of RAC was also analyzed using scanning electron microscopy.The results show that the rheological properties of RAC improve with the increase of VR amount,the plastic viscosity of the paste decreases by 32.8%at 12%of VR amount,the yield stress and plastic viscosity of the mortar decrease by 42.0%and 17.9%,the slump and slump flow increase by 50,40 mm,and the emptying time of inverted slump cylinder is shortened by 65.7%.At the same time,the VR incorporation makes the microstructure of the paste and interface transition zone of RAC become dense,which has a good improvement effect on the strength and durability of RAC.The best improvement is achieved when the VR is incorporated at a amount of 10%,with the 28 d compressive strength and splitting tensile strength of RAC increasing by 7.6%and 17.2%,the water absorption decreasing by 22.6%,and the electric flux and carbonation coefficient decreasing by 47.9%and 29.9%,respectively.In addition,the VR slightly reduces the drying shrinkage of RAC,but increases its early autogenous shrinkage to some extent.

关 键 词：再生骨料混凝土 矿物质降黏剂 流变性能 力学性能 耐久性能 

分 类 号：TU528[建筑科学—建筑技术科学]