钢纤维增强自燃煤矸石轻集料混凝土试验研究

针对煤矸石占用大量耕地并对矿区生态环境造成的污染问题,参照国标,对辽宁省阜新市高德矿排放的自燃煤矸石进行了化学组成、耐久性及有害物质含量、物理力学性能的检测,发现其各项指标均满足国家对轻集料标准的要求.为此,将自燃煤矸石破碎作轻粗集料、钢纤维作增强材料,设计了5组钢纤维掺量的混凝土试件,进行了拌和物工作性及均质性,硬化后抗压强度、劈拉强度和抗折强度的试验,并且以试验结果为样本,建立了钢纤维掺量与混凝土强度之间的定量关系式.研究结果表明,当钢纤维掺量小于2%(体积分数)时,随钢纤维掺量增加,自燃煤矸石轻集料混凝土的抗压?劈拉和抗折强度都有不同程度的提高,其中以抗折强度的增长最为显著.另外,对上述现象进行了机理分析.

Study of Spontaneous Combustion Coal Gangue Steel Fiber Reinforced Lightweight Aggregate Concrete

Coal gangue needs a lot of farmlands to be disposed of and causes pollution problems to the ecological environment in mining area.A systematical tests on chemical constituents,durability and harmful substances content,physical and mechanical properties of the spontaneous combustion coal gangue generated from Gaode,Fuxin City of Liaoning Province were made. With crushed spontaneous combustion coal gangue as the light coarse aggregate that has the performance meeting all requirements set forth in national standard,steel fiber as reinforced material,five specimens with different use level of steel fiber on the basis of all the data meeting the national standards requirement about lightweight aggregate were prepared;workability and homogeneity,compressive strength after hardening,split and tensile strength and flexural strength of the mixture were determined;Based on test results the relationship between steel fiber volume fraction and concrete strength is established.The results show that when the steel fiber volume fraction is less than 2%,with the increase in steel fiber volume,spontaneous combustion coal gangue lightweight aggregate concrete has increasing compressive,tensile and flexural strength with flexural strength being the highest,and the mechanism is analyzed.