再生混凝土骨料改良黄土的力学及微观特性研究  

Study on the mechanical and microscopic properties of recycled concrete aggregate to improve loess

作　　者：邢天佑 高远 李欢凯 张毅豪 翟恺悦 XING Tianyou;GAO Yuan;LI Huankai;ZHANG Yihao;ZHAI Kaiyue(College of Civil Engineering,Henan University of Engineering,Zhengzhou 451191,China)

机构地区：[1]河南工程学院土木工程学院,河南郑州451191

出　　处：《河南工程学院学报（自然科学版）》2024年第3期23-28,共6页Journal of Henan University of Engineering：Natural Science Edition

基　　金：河南省高等学校重点科研项目(22A560010);河南省住房和城乡建设科学技术计划项目(HNJS-2022-K4);河南工程学院博士培育基金项目(D2022018);河南省2023年大学生创新创业训练计划省级项目(S202311517007)。

摘　　要：为探究再生骨料改良黄土强度和微观变化规律,对再生骨料改良黄土及纯黄土开展了三轴试验和扫描电镜微观试验。固结剪切试验结果表明:随含水量的升高,改良黄土与纯黄土试样应力-应变关系由存在明显应力峰值的曲线形态逐渐转变为无显著峰值的应变硬化形态,且掺和再生混凝土骨料的试样相较纯黄土最大轴向应力提高了23%~49%,增长趋势同周围压力近似线性递增。对剪切前后的试样用扫描电镜进行微观试验发现,改良黄土的微观孔隙率与平均颗粒面积随周围压力减少的程度高于纯黄土,即剪切前后改良黄土的微观结构较纯黄土更为密实,印证了其宏观最大轴向应力得到提升的结论。基于回归分析可知,大、小骨料的掺量和含水量对最大轴向应力的影响显著性极高,含水量增加会导致土体强度劣化,大、小骨料掺量增加可提高土体强度。In order to explore the strength and microscopic variation of recycled aggregate improved loess,triaxial tests and scanning electron microscopy tests were carried out on regenerated and improved loess and pure loess.The results of consolidation shear test show that with the increase of water content,the stress-strain relationship between improved loess and pure loess samples gradually changes from a curve with obvious stress peaks to a strain hardening form without significant peaks.Moreover,the ultimate axial stress of the sample mixed with recycled concrete aggregate is increased by 23%~49%compared with that of pure loess,and the growth trend shows an approximate linear relationship with the confining pressure.Electron microscope scanning tests were carried out on the samples before and after shearing.Among them,the microscopic porosity and average particle area of improved loess decrease with confining pressure to a greater extent than that of pure loess,that is,the microstructure of regenerated loess before and after shearing is more compact than that of pure loess,which also confirms the conclusion that its macroscopic ultimate axial stress has been increased.Based on the regression analysis,it was found that the influence of the content and water content of the large and small aggregates on the maximum axial stress was very high,and the increase of water content would lead to the deterioration of soil strength,and the increase of large and small aggregate content could improve the soil strength.

关 键 词：再生骨料 三轴试验 改良黄土 SEM 线性回归分析 

分 类 号：TU45[建筑科学—岩土工程]