摘要
基于深部矿井高应力巷道的隔热与支护问题,并为推动固废资源化利用,以粉煤灰陶粒作为隔热混凝土基料,开展正交试验,探究粉煤灰、玄武岩纤维和麦秆纤维混掺对材料隔热及力学性能的影响;运用功效系数法确定巷道隔热材料最佳配比,借助低场核磁共振和扫描电镜观测试样微观形貌,深入揭示粉煤灰及纤维掺入对试样隔热性能及力学损失的作用机理。结果表明,麦秆纤维对导热系数和抗压强度影响最为显著,玄武岩纤维次之,粉煤灰影响偏小。当粉煤灰以30%质量分数取代水泥,玄武岩纤维和麦秆纤维分别按胶凝料质量的0.5%和6%掺入时,材料导热系数可达最佳0.185 2 W/(m·K),且能为巷道支护起到一定力学辅助支撑作用。在此最佳配比下,粉煤灰填充部分孔隙致使小孔数量减少,而纤维分割内部结构形成空腔并连通部分孔隙,使得整体孔隙率变大,隔热能力得以强化。同时从力学受损形貌看出,纤维与基体紧密粘连,发挥着桥接与延缓裂缝发展的作用,使得样品受损时维持断而不裂状态,有效保留部分力学性能。研究结果可为深部矿井高应力巷道隔热材料研制提供一定参考。
The aim of this study is to address the issue of thermal insulation support for high-stress roadways in deep,thermally-hazardous mines while promoting the utilization of solid waste.An L 16(45)orthogonal test was conducted using fly ash ceramic granules as the base material for lightweight aggregate concrete.The study investigated the effects of three factors—fly ash to cement mass fraction(A),basalt fiber admixture(B),and wheat straw fiber admixture(C)—on various properties of the material,including apparent density,thermal conductivity,compressive strength,water absorption,and porosity.This was achieved through extreme variance analysis,factor-indicator analyses,and analysis of variance.The optimal proportioning ratio for the roadway thermal insulation materials was determined using the coefficient of efficacy method.Using low-field nuclear magnetic resonance and scanning electron microscopy,the pore structures and microscopic morphologies of the samples were examined to elucidate the mechanisms by which fly ash and fibers influence the thermal insulation performance and mechanical properties of the materials.The experimental results indicate that for apparent density,thermal conductivity,compressive strength,and porosity,the priority order of the factors is C,B,and A.In contrast,for the water absorption rate,the priority order is C,A,and B.When the mass of fly ash comprises 30%of the mass of cement,with basalt fiber and wheat straw fiber dosages at 0.5%and 6%of the mass of the cementitious material,respectively,the optimal formulation is achieved.Under this optimal ratio,the material exhibits a thermal conductivity of 0.1852 W/(m·K)and a compressive strength of 13.8 MPa,providing excellent thermal insulation performance along with adequate mechanical support.Under this optimal ratio,fly ash fills some of the pores,thereby reducing the number of small pores.Simultaneously,the incorporation of fibers promotes the formation of internal cavity structures,improves pore geometry,and connects certain pores,resulting in increased overall porosity.The combined effect of the low thermal conductivity of the air within the pores and the fibers themselves enhances the material s thermal insulation capability.The failure morphology of the samples subjected to stress reveals that the fibers in the optimal samples function as a bridging mechanism.This enables the samples to remain fractured but not completely broken after damage,effectively preserving some of their mechanical properties.
作者
杨明
邓辉
蒋亚伟
姚丽敏
周子恒
宋柯燕
YANG Ming;DENG Hui;JIANG Yawei;YAO Limin;ZHOU Ziheng;SONG Keyan(School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,Henan,China;Key Laboratory of Coal Mine Disaster Prevention and Control,Ministry of Education,Jiaozuo 454003,Henan,China;Zhengzhou Institute for Advanced Research of Henan Polytechnic University,Zhengzhou 451464,China;No.10 Mine,Pingdingshan Tianan Coal Company Limited,Pingdingshan 467000,Henan,China)
出处
《安全与环境学报》
北大核心
2025年第6期2166-2178,共13页
Journal of Safety and Environment
基金
国家自然科学基金项目(52274186,52274187)。
关键词
安全工程
热害防治
隔热材料
正交试验
固废利用
safety engineering
thermal damage control
thermal insulation materials
orthogonal tests
solid waste utilization
