原材料对水工大坝混凝土自生体积变形的影响试验研究  

Experimental study on effect of raw materials on autogenous volume deformation of hydraulic dam concrete

作　　者：王建[1] 孔祥芝[2] WANG Jian(Xinjiang Ertsis River Basin Development Project Construction Administration Bureau.Urumqi 830000,Xinjiang,China)

机构地区：[1]新疆额尔齐斯河流域开发工程建设管理局,新疆乌鲁木齐830000 [2]中国水利水电科学研究院,北京100038

出　　处：《水泥》2022年第5期1-5,共5页Cement

基　　金：十三五国家重点研发计划(2?018YFC0406701);国家自然基金项目(51879286);中国水利水电科学研究院基本科研业务费项目(SM0145B032021);新疆额尔齐斯河流域开发工程建设管理局项目(QBT067/FY28)。

摘　　要：自生体积变形是评价大坝混凝土抗裂性能的关键指标之一,但一直以来针对原材料对混凝土自生体积变形的影响缺乏系统全面的试验研究。本文选用三种水泥、四种粉煤灰、两种骨料、两种膨胀剂,采用原材料逐项替换的方式成型大坝全级配和湿筛二级配混凝土试件,测试其自生体积变形。试验结果表明,全级配混凝土的自生体积变形收缩量显著低于湿筛二级配混凝土;随着水泥中MgO含量的增大,混凝土自生体积变形收缩量减小;高钙、高碱粉煤灰混凝土的自生体积变形收缩率增大;相对于花岗岩骨料,灰岩骨料混凝土的自生体积变形收缩量更小;MgO类复合膨胀剂对大坝混凝土自生体积变形具有显著的调节改善作用,但在选用时还需要同时考虑膨胀剂对混凝土微观结构、长期力学性能、耐久性等各项性能的影响。Autoge nous volume deformatio n is one of the key indexes to evaluate the crack resista nee of dam concrete,but there has been a lack of systematic and comprehensive experimental research on the influence of raw materials on autogenous volume deformation of concrete.In this paper,three kinds of cement,four kinds of fly ash.two kinds of aggregate and two kinds of expansion agent were used to pour full-graded and wet screened dam concrete by replacing material one by one,and its autogenous volume deformation is tested.The test results showed that the autogenous volume deformation shrinkage of full-graded con Crete was less than that of wet screened concrete.The autogenous volume detormation of con crete decreased with the increase of MgO contenl in cement.High calcium and high alkali fly ash was unfhvorable to the autogenous volume deformation of concrete.Compared with granite aggregate,the autogenous volume deformation shrinkage of limestone aggregate con crete was smaller.MgO compound expansive age nt can significantly adjust and improve the autoge nous volume deformation of the dam con crete,but the influe nee of expansive agent on the microstructure,long-term mecha nics and durability of concrete should be considered when selecting it.

关 键 词：水工混凝土 原材料 自生体积变形 膨胀剂 

分 类 号：TU528.04[建筑科学—建筑技术科学]