摘要
为快速高效解决钢渣安定性问题,研究了巴氏芽孢杆菌微生物改性钢渣安定性用的材料因素(微生物浓度、尿素浓度)和处置方法(处置时间、处置温度)对钢渣安定性和抗压强度的影响,并通过X射线衍射分析仪、扫描电子显微镜等手段分析不同因素对微生物改性钢渣性能影响效果机制.在此基础上,将改性合格的钢渣应用于道路基层,测定其试件的7 d无侧限抗压强度和浸水膨胀率.研究结果表明:1)利用巴氏芽孢杆菌微生物可以有效的改善钢渣的体积安定性.当微生物掺量为钢渣质量的60％,尿素浓度2 mol/L,处置温度(20±2)℃,处置时间72 h时,微生物对钢渣中安定性处置效果最好,此时钢渣中游离氧化钙(f-CaO)含量为2.98％,符合YB/T 4184-2018《钢渣集料混合料路面基层施工技术规范》要求.2)利用改性钢渣制备道路基层材料,当水泥掺量为6％时,高速和一级公路基底层、二级及二级以下的公路基底层,和二级及以下公路基层的7 d无侧限抗压强度分别为4.1 MPa、4.6 MPa、5.1 MPa,与未改性前相比分别提升了 20.6％、9.5％、8.5％,浸水膨胀率分别是1.77％、1.84％、1.92％,均符合YB/T 4184-2018中浸水膨胀率＜2％的要求.
Abstract
In order to quickly and efficiently solve the stability problem of steel slag,this paper studied the effects of material factors(microbial concentration,urea concentration)and treatment methods(treatment time,treatment temperature)on the stability and compressive strength of steel slag modified by Bacillus Pasteuris.The impact of the above factors on the properties of microbe-modified steel slag was analyzed using X-ray diffraction analyzer,scanning electron microscope,and other testing methods.On this basis,the modified steel slag was applied to the road base,and the 7-day unconfined compressive strength and water-soaked expansion rate of the specimen were studied.The results showed that:1)the volume stability of steel slag could be effectively improved by using Bacillus pasteuris.When the microbial content was 60％of the mass of steel slag,the urea concentration was 2 mol/L,the treatment temperature was(20±2)℃,and the treatment time was 72 h,the treatment effect of microbial on steel slag was the best,and the content of f-CaO in steel slag was 2.98％,which met the requirements of the code.2)using modified steel slag to prepare road base material,when the cement content was 6％,the 7-day unconfined compressive strength of the base course of Expressway and class Ⅰ highway,the base course of class Ⅱ and below highways,and the base-bottom course of class Ⅱ and below highways are 4.1 MPa,4.6 MPa and 5.1 MPa,respectively.Compared with the specimens before modification,they were increased by 20.6％,9.5％,and 8.5％,respectively.The water-soaked expansion rates were 1.77％,1.84％,and 1.92％,respectively,which all met the requirements in the code of less than 2％.
基金项目
国家自然科学基金项目(52178264)
国家自然科学基金项目(52178265)
国家自然科学基金项目(52278268)
国家自然科学基金项目(52278269)
天津市重点研发计划科技支撑重点项目(20YFZCSN00520)
中国铁建股份有限公司科技重大专项(2020-A01)
中铁建大桥工程局集团科技创新项目(DQJ-2021-A03)
NETL
NSTL
万方数据