摘要
钢渣经过破碎筛分,可作为一种高性能的绿色砂石替代产品,在公路工程领域具有广阔的前景。然而,由于存在游离的CaO和MgO,钢渣碎石体积稳定性较差,限制了其在道路施工中直接使用。为解决上述问题,利用嗜碱芽孢杆菌对钢渣碎石进行协同碳化处理,通过不同菌液浓度下的碳化钢渣碎石室内试验,系统分析了钢渣碎石的碳化增重率、压实特性和浸水膨胀率的变化规律。结果表明,微生物的加入显著提高了钢渣的碳化程度,与传统直接湿法碳化相比,碳化增重率增加了57%~236%。根据微生物的协同碳化效果,确定了最优的菌液浓度为20 mg/L,这使得碳化后钢渣级配碎石的最大干密度达2.775 g/cm^(3),10 d的浸水膨胀率仅为1.74%,满足道路基层材料的体积稳定性要求。由压实前后的颗粒筛分结果可知,在碳化时的微生物含量越高,压实过程中钢渣碎石的颗粒破碎越显著,且分形维数的相对变化与含水率之间呈线性正相关关系。本研究验证了微生物协同碳化在改善钢渣碎石工程性质方面的可行性,为钢渣碎石在道路基层施工中的高效利用提供了一种有效的解决方案。
After crushing and sieving,steel slag can serve as a high-performance green sand and aggregate substitute,with broad prospects in the field of road engineering.However,due to the presence of free CaO and MgO,the volume stability of steel slag crushed stone is relatively poor,limiting their direct application in road construction.To solve the aforementioned problem,the synergistic carbonization of steel slag crushed stone was treated by using bacillus alkaliphilic,and the carbonization weight gain rate,compaction characteristics and expansion rate after immersion were systematically analyzed through the laboratory tests,where the carbonated steel slag crushed stone was prepared with different bacterial liquid concentrations.The results showed that the addition of microorganisms significantly improved the carbonation degree of the steel slag,with a 57%~236%increase in carbonation weight gain compared to traditional direct wet carbonation.Based on the synergistic carbonation effect of the microorganisms,an optimal bacterial concentration of 20 mg/L was determined,which resulted in a maximum dry density of 2.775 g/cm^(3)and a 10 day immersion expansion rate of only 1.74%for the carbonated steel slag graded crushed stone,meeting the volume stability requirements for road base materials.The particle size analysis before and after compaction revealed that the higher the microbial content during carbonation,the more significant the fragmentation of the steel slag crushed stone during the compaction process.Moreover,the relative change in fractal dimension showed a linear positive relationship with the moisture content.This study has verified the feasibility of microbial-assisted carbonation in improving the engineering properties of steel slag crushed stone,providing an effective solution for the efficient utilization of steel slag crushed stone in road base construction.
作者
李崛
秦誉榕
刘正楠
张孝彬
LI Jue;QIN Yurong;LIU Zhengnan;ZHANG Xiaobin(National&Local Joint Engineering Research Center of Transportation and Civil Engineerring Materials,Chongqing Jiaotong University,Chongqing 400074,China;Chuzhou University,Chuzhou,Anhui 239099,China;Hunan Communications Research Institute Co.,Ltd.,Changsha,Hunan 410114,China)
出处
《公路工程》
2025年第3期84-90,共7页
Highway Engineering
基金
重庆市自然科学基金面上项目(CSTB2024NSCQ-MSX1177)
安徽省公路低碳材料工程研究中心开放课题项目(HLCM2024G04)。
关键词
道路工程
钢渣
碳化
级配碎石
压实特性
微生物改良
road engineering
steel slag
carbonation
graded crushed rock
compaction characteristics
microbial improvement
