不同品质粉煤灰在煤矿安全中应用效果试验研究

Experimental Study on Application Effect of Different Quality Fly Ash in Coal Mine Safety

我国煤矿生产事故频发,顶板垮落、瓦斯爆炸、机电事故、突水、矿井火灾、放炮等隐患时刻影响着煤矿安全生产,当前矿井开采以井下开采为主,井下开采存在技术要求高、开采难度大的问题,导致煤矿事故发生数和死亡人数相对其他行业居于首位。因此,为改善煤矿事故发生情况,提高煤矿安全生产,将粉煤灰应用到煤矿生产中,替代部分水泥,降低成本,降低混凝土水化热及渗透性,提高灌注混凝土工作性与耐久性。通过试验验证表明:采用Ⅰ级粉煤灰的混凝土较采用Ⅱ级粉煤灰的混凝土抗压强度、轴拉强度和极限拉伸值均略高,且干缩率较低,掺加Ⅱ级粉煤灰的混凝土的抗冻性能优于掺加I级粉煤灰的混凝土,I级粉煤灰对混凝土抗冻性能负面影响严重。同强度等级、同水胶比条件下,Ⅰ级粉煤灰混凝土抗冲磨强度比Ⅱ级粉煤灰混凝土抗冲磨强度及抗水冲蚀能力稍高,对预防及应对煤矿安全问题具有重要意义。

Coal mine accidents occur-frequently in china,roof caving,gas explosion,mechanical and electrical accidents,water inrush,mine fire,blasting and other hidden dangers affecting the safety of coal mine production at all times.At present,coal mine mining is mainly underground mining,which has high technical requirements and mining difficulties,leading to the number of coal mine accidents and deaths in the first place compared with other industries.Therefore,in order to improve the occurrence of coal mine accidents and improve the safety of coal mine production,fly ash was applied to coal mine production to replace part of cement,to reduce the cost,as well as to reduce the hydration heat and permeability of concrete,and improve the workability and durability of pouring concrete.The test results show that the compressive strength,axial tensile strength and ultimate tensile value of the concrete with class I fly ash are slightly higher than those with class II fly ash,and the dry shrinkage rate is lower.The frost resistance of the concrete with class II fly ash is better than that of the concrete with class I fly ash,and the negative impact of class I fly ash on the frost resistance of the concrete is serious.Under the condition of the same strength grade and water binder ratio,the impact and wear resistance of grade I fly ash concrete is slightly higher than that of grade II fly ash concrete,which is of great significance to prevent and deal with coal mine safety problems.