温度对高寒矿山湿喷混凝土强度影响规律及工程应用研究  

The effect of temperature on strength of wet shotcrete in cold mining areas and its engineering application

作　　者：姚松[1,2] 韩斌[2] 吴爱祥[2] 蒋先尧 龚开福 石勇 

机构地区：[1]中色非洲矿业有限公司,赞比亚基特韦22592 [2]北京科技大学金属矿山高效开采与安全教育部重点实验室,北京100083 [3]吉林板庙子矿业有限公司,吉林白山134300

出　　处：《采矿与安全工程学报》2017年第2期384-390,共7页Journal of Mining & Safety Engineering

基　　金：国家"十二五"科技支撑计划项目(2012BAB08B02);新世纪优秀人才支持计划项目(NECT-07-0669);国家自然科学基金项目(50774011);教育部长江学者和创新团队发展计划项目(IRT0950)

摘　　要：以吉林金英金矿湿喷混凝土强度发展缓慢、易开裂等问题为研究背景,分别研究了料浆温度和养护温度对湿喷混凝土强度发展的影响规律,采用扫描电子显微镜(SEM)对湿喷混凝土的微观结构进行分析。结果表明:料浆温度对湿喷混凝土早期强度发展影响显著,温度越高达到准入强度(1 MPa)时间越短;养护温度对湿喷混凝土的后期强度影响较大,尤其在低温区(<10℃)影响显著;温度影响混凝土的微观结构从而影响其宏观力学特性,当温度较低时(<2℃)湿喷混凝土微观结构疏松,存在大量孔隙和贯穿性缝隙,随温度升高,微观结构中孔隙和贯穿性裂缝明显减少,空间网络结构趋于密实。通过提高料浆温度和养护温度改进工艺,成功解决了金英金矿湿喷混凝土支护准入时间过长、喷层强度低、易开裂等问题,使金英金矿巷道湿喷混凝土施工准入时间缩短90 min,巷道掘进速度提高27%,后期强度提高49%,巷道返修率几乎为零,井下生产效率提高14%。Facing issues like slow development of shotcrete strength and its high cracking tendency in Jinying gold mine, the influence rule of mortar temperature and curing temperature on shotcrete strength development was studied respectively, and the microstructure of the shotcrete was analysed with Scan- ning Electron Microscope （SEM）. The results have shown that mortar temperature has a significant ef- fect on： the higher mortar temperature, the less time needs to achieve the re-entry strength （1 MPa）; curing temperature has a significant effect on late shotcrete strength development, especially when thetemperature is very low （lower than 10 ~C）; temperature affects microstructure of wet shotcrete and fur- ther affects its macro-mechanical properties： the microstructure of shotcrete is relatively loose with lots of pores and penetrating cracks at low temperature （lower than 2 ~C）; with the increase of temperature, the quantity of the pores and penetrating cracks significantly decreases, and the spatial network struc- tural density increases. Problems related to wet shotcrete like long re-entry time, low layer strength and high cracking tendency are solved through increasing mortar temperature and curing temperature： the re-entry time reduces by 90 minutes, tunneling speed increases by 27%, later strength increases by 49%, in the repair rate of roadway support drops nearly to O, and the production efficiency of Jinying gold mine increases by 14%.

关 键 词：高寒矿山 湿喷混凝土 早期强度 后期强度 影响机理 

分 类 号：TD853[矿业工程—金属矿开采]