MICP增强改性煤矸石在水稳材料中应用的试验研究  

Experimental Study on Application of MICP Modified Coal Gangue in Cement Stabilized Material

作　　者：贾冠华[1,2] 贾佳 刘玮 李珠[3] JIA Guan-hua;JIA Jia;LIU Wei;LI Zhu(School of Electric Power,Civil Engineering and Architecture,Shanxi University,Taiyuan,Shanxi 030031,China;Trial-produce Center for Smart Building and Green Construction Technology of Shanxi Province,Shanxi University,Taiyuan,Shanxi 030031,China;College of Civil Engineering,Taiyuan University of Technology,Taiyuan,Shanxi 030024,China)

机构地区：[1]山西大学电力与建筑学院,山西太原030031 [2]山西大学山西省智慧建筑与绿色建造技术中试基地,山西太原030031 [3]太原理工大学土木工程学院,山西太原030024

出　　处：《公路交通科技》2024年第3期50-60,共11页Journal of Highway and Transportation Research and Development

基　　金：山西省中央引导地方科技发展资金项目(YDZJSX2022B018)。

摘　　要：为解决煤矸石集料强度低、吸水率高、易崩解等问题,采用微生物诱导碳酸盐沉积(MICP)技术对煤矸石进行了增强改性。通过表观密度、吸水率、压碎值和超声波质量损失率的测试,同时结合SEM,EDS和XRD微观表征,研究了微生物矿化时间、菌液浓度和煤矸石粒径对MICP增强改性煤矸石性能的影响,并揭示了MICP增改性煤矸石的机理。将MICP增强改性煤矸石应用于水稳材料,通过无侧限抗压强度、间接抗拉强度和抗压回弹模量的测试,对比了MICP增强改性煤矸石水稳材料与普通煤矸石水稳材料的性能。结果表明:采用MICP增强改性技术可以提升煤矸石的物理力学性能,并且煤矸石的粒径越大增强改性效果越明显;在菌液OD600值(溶液在600 nm波长处的吸光值)为0.8、矿化改性7 d的条件下,MICP增强改性煤矸石比普通煤矸石的表观密度增加了14.66%,吸水率降低了40.94%,压碎值降低了7.93%;经MICP增强改性后的煤矸石表面包裹的生物CaCO_(3)方解石使得煤矸石的表观密度增加,吸水率和压碎值降低,强度提高,从而提升了煤矸石的性能;水泥稳定MICP增强改性煤矸石混合料最佳含水量比普通煤矸石水稳材料降低了17.3%,最大干密度增加了7.9%;MICP增强改性煤矸石水稳材料各龄期的无侧限抗压强度、间接抗拉强度和抗压回弹模量比普通煤矸石水稳材料均显著提升,表现出更高的强度、更好的抗裂性能和抗变形能力。In order to solve the problems of coal gangue with low strength,high water absorption and easy disintegration,the microbial induced carbonate precipitation(MICP)technology is used to strengthen and modify coal gangue.Through testing the apparent densities,water absorptions,crushing values and ultrasonic mass loss rate,and combining with the microscopic characterization of SEM,EDS and XRD,the effects of microbial mineralization time,concentration of bacteria solution and particle size of coal gangue on the performance of MICP modified coal gangue are studied,and the mechanism of MICP modifying coal gangue is revealed.The MICP modified coal gangue is applied to cement stabilized materials,and the properties of cement stabilized materials of MICP modified coal gangue and ordinary coal gangue are compared by testing unconfined compressive strength,splitting strength and compression modulus of resilience.The result shows that the MICP technology can improve the physical and mechanical properties of coal gangue.The larger the particle size of coal gangue are,the more obvious the MICP enhanced and modified effect are.Under the conditions that the OD600(absorbance value of solution at 600 nm wavelength)value of bacterial solution is 0.8 and biomineralization time is 7 d,the apparent density of MICP modified coal gangue increases by 14.66%,the water absorption rate decreases by 40.94%,and the crushing value decreases by 7.93%compared with ordinary coal gangue.The biological CaCO_(3)coated on the surface of coal gangue after MICP modification are calcite,which improve the performances of coal gangue,such as increasing the apparent density of coal gangue,decreasing the water absorption and crushing value and adding strength.Compared with the ordinary coal gangue,the optimum water content of cement stabilized materials of MICP modified coal gangue is decreases by 17.3%,and the maximum dry density increases by 7.9%.The unconfined compressive strength,indirect tensile strength and compression modulus of resilience of cement st

关 键 词：道路工程 水稳材料 微生物诱导碳酸钙沉积(MICP) 煤矸石 增强改性 

分 类 号：U414[交通运输工程—道路与铁道工程]