掺低活性矿渣砂浆的自养护效应对性能影响的试验研究  

Experimental Study on Self-Curing Effect on Performance of Mortar with Low Active Slag

作　　者：李双喜[1,2] 钱婷 姜春萌 LI Shuang-xi;QIAN Ting;JIANG Chun-meng(School of Hydraulic and Civil Engineering,Xinjiang Agricultural University,Urumqi 830052,China;Key Laboratory of Water Conservancy Project Safety and Water Disaster Prevention,Urumqi 830052,China)

机构地区：[1]新疆农业大学水利与土木工程学院,乌鲁木齐830052 [2]新疆水利工程安全与水灾害防治重点实验室,乌鲁木齐830052

出　　处：《新疆农业大学学报》2022年第6期501-507,共7页Journal of Xinjiang Agricultural University

基　　金：新疆维吾尔自治区自然科学基金项目(2019D01A46)。

摘　　要：采用低活性矿渣代替部分砂作为内养护材料,研究不同掺量的低活性矿渣对低水灰比水泥砂浆力学性能及内养护性能的影响,并通过显微硬度测试、内部相对湿度测试以及扫描电子显微镜(SEM)对低活性矿渣减缩机理进行分析。结果表明,低活性矿渣对砂浆早期影响大,抗压强度及界面区强度在低活性矿渣释水后均出现下降;砂浆后期强度在低活性矿渣火山灰效应和内养护效应的叠加作用下迅速增长并超过对照组,15%低活性矿渣掺量的砂浆7~28 d强度增长率可达71.5%;低活性矿渣具有良好的吸水释水性能,能有效弥补砂浆的内部相对湿度损失,减小自收缩产生的原动力;低活性矿渣与界面区水化产物紧密搭接,显著改善了砂浆的界面区结构。Using low active slag to replace part of sand as internal curing material,the effects of different contents of low active slag on the mechanical properties and internal curing properties of low water-binder ratio cement mortar were studied,and the shrinkage reduction mechanism of low active slag was analyzed through microhardness test,internal relative humidity test and scanning electron microscope(SEM).The results showed that:Low active slag had a great influence on the early stage of mortar,and the compressive strength and interfacial transition zone strength decreased after the low active slag released water.Under the superposition of pozzolanic effect and internal curing effect of low activated slag,the late strength of mortar increased rapidly and exceeded the control group.The strength growth rate of mortar with 15%low active slag content could reach 71.5%during 7-28 d.Low active slag had good water absorption and release performance,which could effectively compensate for the internal relative humidity loss of mortar and reduce the driving force of autogenous shrinkage.The low active slag was closely overlapped with the hydration products of the interfacial transition zone,which significantly improved the structure of the interfacial transition zone of the mortar.

关 键 词：内养护 自收缩 内部相对湿度 低活性矿渣 界面过渡区 

分 类 号：TU525.9[建筑科学—建筑技术科学]