高水充填材料失稳破坏特征研究及性能改善

发布时间：2018-02-27 19:26

本文关键词： 采矿充填材料失稳破坏蠕变　出处：《煤炭学报》2017年05期 　论文类型：期刊论文

【摘要】：针对高水充填材料强度低、稳定性差等问题,对高水充填材料的性能进行改善,并通过应力-应变和蠕变试验,研究高水充填材料失稳破坏特征;通过扫描电镜与差热-热重实验,研究高水充填材料的微观结构与高水充填材料的改善机理。结果表明:高水充填材料在应力水平较小时,蠕变曲线有衰减蠕变和稳定蠕变2个阶段;当应力水平达到临界荷载时,蠕变曲线出现加速蠕变阶段;应力-应变关系曲线宏观上有4个阶段:初始变形阶段,弹性阶段,塑性变形阶段和破坏阶段;改善后的高水充填材料胶凝时间缩短,抗压强度提高,弹性模量增大,失稳破坏的临界荷载提高,变形减小;改善后的高水充填材料生成更多的钙矾石晶体和铝胶,硬化体微观结构更致密,有利于提高充填体的承载能力。
[Abstract]:Aiming at the problems of low strength and poor stability of high water filling material, the performance of high water filling material is improved, and the characteristics of instability and failure of high water filling material are studied through stress-strain and creep test. The microstructure of high water filling material and the improvement mechanism of high water filling material were studied by scanning electron microscope and differential thermogravimetric test. The results showed that the stress level of high water filling material was low. The creep curve has two stages: attenuated creep and stable creep; when stress level reaches critical load, creep curve appears accelerated creep stage; stress-strain relation curve has four stages macroscopically: initial deformation stage, elastic stage, elastic phase, and strain curve. The improved high water filling material has shorter cementing time, higher compressive strength, higher elastic modulus, higher critical load and smaller deformation. More ettringite crystals and aluminum gel are formed from the improved high water filling materials, and the microstructure of hardened materials is more compact, which is beneficial to the improvement of the loading capacity of the fillers.
【作者单位】：北京科技大学土木与资源工程学院;城市地下空间工程北京市重点实验室;
【基金】：国家自然科学基金资助项目(51374036)
【分类号】：TD823.7

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