不同纤维调控水泥基胶结充填体强度性能研究  

Study on Strength Performance of Cementitious Backfill Regulated by Different Fibers

作　　者：陶博识 刘卫星[2] TAO Boshi;LIU Weixing(College of Civil Engineering,Jilin Technology College of Electronic Information,Jilin,Jilin 132021,China;College of Civil Engineering,Northeast Electric Power University,Jilin,Jilin 132000,China)

机构地区：[1]吉林电子信息职业技术学院建筑工程学院,吉林吉林市132021 [2]东北电力大学建筑工程学院,吉林吉林市132000

出　　处：《矿业研究与开发》2022年第9期122-128,共7页Mining Research and Development

基　　金：国家自然科学基金项目(52078108);吉林省职业教育科研课题(2021XHY108);吉林省职业教育与成人教育教学改革研究课题(2020ZCY413)。

摘　　要：为了提高充填体稳定性和采空区充填质量,采用聚丙烯纤维、聚丙烯腈纤维和玻璃纤维作为增强剂,探讨了3种纤维不同掺量对尾砂胶结充填体力学性能的影响规律,比较了掺纤维和无纤维作用下胶结充填体的破坏模式,采用扫描电子显微镜揭示了掺纤维尾砂胶结充填体水化机理。试验结果表明,胶结充填体抗压强度随着纤维掺量的增加呈先上升后降低的趋势,当纤维掺量为0.6%时,充填体抗压强度达最大值,从强度增益效果来看,聚丙烯纤维最好,聚丙烯腈纤维次之,玻璃纤维最差。纤维对充填体抗折强度增益效果优于抗压强度的增益效果,当聚丙烯纤维掺量为0.9%,聚丙烯腈纤维掺量为1.2%,玻璃纤维掺量为1.2%时,胶结充填体抗折强度达最大值,掺纤维胶结充填体3 d、7 d、14 d和28 d最大抗折强度增幅为157.89%、216.00%、217.86%、143.40%。在单轴荷载破坏作用下,无纤维充填体试块出现多条长且宽的贯穿性裂纹,边角部位伴有较多碎块脱落,而掺纤维充填体试块仅出现细短微裂纹,试块保持较高的完整性。掺纤维充填体水化产物以钙矾石、C—S—H凝胶和Ca(OH)_(2)为主,纤维与充填体基体交界处被大量水化产物包裹,能够有效抑制裂缝扩展,增强充填体结构的黏结力和抵抗外界变形的能力,使充填体保持较高的力学性能。In order to improve the stability of filling body and the filling quality of goaf, polypropylene fiber, polyacrylonitrile fiber and glass fiber were used as reinforcing agents. Then, the influence laws of the different adding amounts of the three fibers on the mechanical properties of the tailings cemented filling body were explored, and the damage pattern of the cemented filling body under the action of adding fiber and no fiber was compared. The hydration mechanism of tailings cemented filling body with fiber was revealed by scanning electron microscope. The test results are concluded as follows. The compressive strength of the cemented filling body increases firstly and then decreases with the increase of fiber dosing, and the compressive strength of the filling body reaches the largest when the fiber dosing is 0.6%. In terms of strength gain effect, polypropylene fiber is the best, polyacrylonitrile fiber is the second, and glass fiber is the worst. The gain effect of fiber on the flexural strength of filling body is better than that of compressive strength. When polypropylene fiber dosing is 0.9%, polyacrylonitrile fiber dosing is 1.2% and glass fiber dosing is 1.2%, the flexural strength of the cemented filling body reaches the largest, and the maximum flexural strength gain degree of cemented filling body with fiber at 3 d, 7 d, 14 d and 28 d is 157.89%, 216.00%, 217.86%, 143.40%. Under the action of uniaxial load failure, there are many long and wide penetrating cracks in the non-fiber filling body test block, and there are many fragments falling off at the corners. However, there are only short micro-cracks in the fiber-doped filling body test block, and the test block maintains high integrity. The hydration products of the filling body with fiber are mainly calcium alumina, C—S—H gel and Ca(OH)_(2), and the junction of fiber and filling body matrix is wrapped by a large amount of hydration products, which can effectively inhibit the crack expansion, increases the bonding force and resistance to exte

关 键 词：尾砂 纤维 力学性能 破坏模式 水化机理 

分 类 号：TD853.34[矿业工程—金属矿开采]