钢渣-水泥改良红层填料无侧限抗压强度试验研究  

Experimental study on unconfined compressive strength of steel slag-cement modified red-layer filling

作　　者：余云燕[1] 王堃[1] 张杨 包得祥 杜乾中 朱明哲 黄志勤 YU Yunyan;WANG Kun;ZHANG Yang;BAO Dexiang;DU Qianzhong;ZHU Mingzhe;HUANG Zhiqin(School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou,Gansu 730070,China;Gansu New Urban Development&Construction Operation Group Co.,Ltd.,Lanzhou,Gansu 730070,China)

机构地区：[1]兰州交通大学土木工程学院,甘肃兰州730070 [2]甘肃新发展城市开发建设运营集团有限公司,甘肃兰州730070

出　　处：《公路交通科技》2025年第4期69-77,共9页Journal of Highway and Transportation Research and Development

基　　金：甘肃省科技计划项目(21YF5GA050);甘肃省交通运输厅科技研发项目(2021-12);甘肃省教育厅产业支撑计划项目(2021CYZC-28);甘肃省基础研究创新群体项目(145RJIA332,21JR7RA347)。

摘　　要：【目标】针对红层泥岩填料遇水软化的特性,以兰州地区红层泥岩路基填料为研究对象,采用钢渣和水泥对红层泥岩填料进行改良。【方法】通过无侧限抗压强度试验,研究不同改良剂种类、掺量、压实度、养护龄期条件下改良土试样无侧限抗压强度的变化规律,并对比浸水前后强度损失率与崩解性的改善情况。【结果】随着钢渣掺量的增加,改良土试样的最优含水率逐渐减小,最大干密度逐渐增大;无侧限抗压强度随改良剂掺量、压实度与养护龄期的增加而增大;然而,钢渣掺配量存在上限值,水泥掺配量存在下限值,相较于单一改良法,复合改良法激发了钢渣的潜在胶凝性,改良效果更佳。扫描电镜显示钢渣-水泥复合改良的方式能够有效增强土颗粒间的联结作用,并有助于提高土体的强度与稳定性。当钢渣掺量≥10%且水泥掺量≥2%时,改良土试样无侧限抗压强度损失率接近50%且崩解性逐渐减小。【结论】高速公路和一级公路路床的红层泥岩填料、钢渣、水泥最佳掺配比为100∶15∶2,路堤的最佳掺配比为100∶10∶2。钢渣-水泥复合改良土试样的无侧限抗压强度随压实度与养护龄期的增加而增大,但增加养护龄期提高浸水强度的效果更佳。[Objective]Aiming at softening characteristics of red-layer mudstone filling in water,taking red-layer mudstone filling in Lanzhou as the study object,the steel slag and cement were used to modify the red-layer mudstone filling.[Method]The variation rule of modified soil specimens’unconfined compressive strength with different modifier types,contents,compaction degrees and curing periods were studied through unconfined compressive strength tests.The improvements of strength loss rate and disintegration were compared before and after water immersion.[Result]With the increase of steel slag contents,the optimum water content of modified soil specimens gradually decreases,and the maximum dry density gradually increases.The unconfined compressive strength increases with the increase of modifier content,compaction degree and curing period.However,there is an upper limit value for steel slag content,and a lower limit value for cement content as well.Compared with a single modification method,the composite modification method stimulates the potential cementation of steel slag with better modification effect.Scanning electron microscopy results indicate that the steel slag-cement composite modification method effectively enhances the linkage among soil particles,improving the strength and stability of soil.When the steel slag content≥10%and the cement content≥2%,the unconfined compressive strength loss rate of modified soil specimen is close to 50%,and the disintegration gradually decreases.[Conclusion]For expressways and first grade highways,the optimum mix proportion of red-layer mudstone filling,steel slag,and cement is 100∶15∶2,and for road embankment is 100∶10∶2.The unconfined compressive strength of steel slag-cement composite modified soil specimens increases with the increases of compaction degree and curing period,while the improvements of curing period and immersion strength have better effects.

关 键 词：道路工程 红层泥岩填料 钢渣-水泥改良 无侧限抗压强度 强度损失 扫描电镜 

分 类 号：U416.1[交通运输工程—道路与铁道工程]