水泥改良高液限红黏土抗拉强度试验研究  

Experimental Study on the Tensile Strength of Cement Modified High Liquid Limit Red Clay

作　　者：韦秉旭[1] 吴佳雪 陈楚方 WEI Bing-xu;WU Jia-xue;CHEN Chu-fang(College of Transportation Engineering,Changsha University of Science&Technology,Changsha 410114,China;Guangxi Road Construction Engineering Group Co.Ltd,Nanning 530029,China)

机构地区：[1]长沙理工大学交通运输工程学院,长沙市410114 [2]广西路建工程集团有限公司,南宁市530029

出　　处：《公路》2024年第10期330-335,共6页Highway

基　　金：国家自然科学基金项目,项目编号52178413;湖南省自然科学基金项目,项目编号2018JJ2431。

摘　　要：为揭示水泥改良高液限红黏土拉伸强度的影响因素,以长沙市某高液限红黏土为研究对象,使用单柱拉伸仪器和改良后的拉伸夹具开展直接拉伸试验,探讨不同水泥掺量(A)、初始含水率(w)、初始干密度(ρd)、养护时间(t)和拉伸速率(ν)条件下水泥改良高液限红黏土抗拉强度的演化规律。研究表明:水泥改良红黏土的抗拉强度总体上随水泥掺量的增加而增加,但在掺量达到6%之后增长趋势减缓;随初始含水率的增加,抗拉强度呈现出先增大后减小的趋势,且在最佳含水率附近处达到峰值;同时,抗拉强度与初始干密度、养护龄期呈正相关关系;拉伸速率越大试件的抗拉强度越大。建立了水泥改良红黏土抗拉强度关于水泥掺量、养护龄期、拉伸速率等影响因素之间的非线性关系式,拟合效果理想。综合考虑各因素对水泥改良红黏土抗拉强度的影响,从技术经济角度考虑,建议长沙地区红黏土水泥改良最佳掺量为6%。To reveal the influencing factors on the tensile strength of cement modified high liquid limit red clay,a high liquid limit red clay in Changsha is taken as the research object,and direct tensile tests are caried out by using a single column tensile instrument and improved tensile fixtures to explore the evolution law of tensile strength of cement modified high liquid limit red clay under different cement content(A),initial moisture content(w),and initial dry density(pa),curing time(t)and stretching rate(v).Research shows that:the tensile strength of cement modified red clay generally increases with the increase of cement content,but the growth trend slows down after the cement content reaches 6%;as the initial moisture content increases,the tensile strength shows a trend of first increasing and then decreasing,and reaches peak value near the optimal moisture content;at the same time,the tensile strength is positively correlated with the initial dry density and curing period;the higher the tensile rate,the greater the tensile strength of the specimen.A nonlinear relationship between the tensile strength of cement modified red clay and factors such as cement content,curing age,and tensile rate has been established,and the fitting effect is ideal.Taking into account the impact of various factors on the tensile strength of cement modified red clay,from a technical and economic perspective,it is recommended that the optimal cement content for improving red clay in Changsha areas be 6%.

关 键 词：水泥改良红黏土 水泥掺量 养护龄期 拉伸速率 抗拉强度 

分 类 号：U416.1[交通运输工程—道路与铁道工程] TU472[建筑科学—结构工程]