冻融循环对全尾砂固结体强度与微观孔结构的影响  

Effect of Freeze-thaw Cycles on Mechanical Strength and Microscopic Pore Structure of Unclassified Tailings Cemented Mass

作　　者：侯运炳[1] 丁鹏初 韩冬 张兴 曹曙雄 郭勤强 HOU Yunbing;DING Pengchu;HAN Dong;ZHANG Xing;CAO Shuxiong;GUO Qinqiang(School of Resources and Safety Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;Institute of Geological&Mineral Resources Survey of Henan,Luoyang,Henan 471023,China)

机构地区：[1]中国矿业大学(北京)资源与安全工程学院,北京100083 [2]河南省地矿局第一地质矿产调查院,河南洛阳市471023

出　　处：《矿业研究与开发》2019年第8期68-73,共6页Mining Research and Development

基　　金：国家自然科学基金面上项目(51674263);中央高校基本科研业务费专项基金项目(2011YZ02)

摘　　要：通过实验室试验,对冻融循环作用下全尾砂固结体强度与孔结构演化规律进行了研究。以含有自制胶凝材料TC-Ⅰ的全尾砂固结体为试验对象,运用抗折抗压试验机与压汞仪分别对标准养护条件下与冻融20次后的试件进行了力学与压汞试验,并通过理论推导得出损伤量D。研究结果表明:养护3d时的强度低于其冻融20次的强度,7d后的强度有所反超;标准养护条件下的孔隙率、总孔隙量、孔总面积、平均孔径4个全尾砂固结体内部孔结构参数均随养护时间的增长而减小,冻融循环20次后的孔结构参数变化规律与之相反,且其推导出的损伤量D与强度关系为:D=-0.184σ+0.5479;从强度与孔结构参数变化规律可以看出,35g/L的防冻剂掺量降低了冻融循环对全尾砂固结体的破坏作用。The evolution law of strength and pore structure of the unclassified tailings cemented mass under freeze-thaw cycles were studied by the laboratory test method.The unclassified tailings cemented mass containing the self-made cementing material TC-Ⅰ was used as the test object.At the same time,the constant stress compression testing machine and mercury injection apparatus were exerted to conduct the mechanics and mercury intrusion test on specimens after normal cure and twenty freeze-thaw cycles,and the amount of damage D was derived theoretically.The results were concluded as follows.Firstly,the strength with curing time of three days was lower than that of twenty freeze-thaw cycles,but the strength was reversed after seven days of curing time.Secondly,under standard curing condition,four internal pore structure parameters of unclassified tailings cement mass,such as porosity,total pore volume,total pore area and average pore diameter were all decreased with the increase of curing time,while the variation law of the pore structure parameters was opposite after twenty freeze-thaw cycles.And the relationship between the amount of damage Dand the strength was:D=-0.184σ+0.5479.From the variation law of the strength and the pore structure parameters,it can be concluded that the damage of the freeze-thaw cycle to unclassified tailings cemented mass was reduced by the anti-freeze with a content of 35 g/L.

关 键 词：全尾砂固结体 冻融循环 抗压强度 孔结构参数 压汞试验 损伤 

分 类 号：TD853[矿业工程—金属矿开采]