变温变湿条件下早强水泥稳定碎石的断裂性能  

Cracking Characteristics of Cement-Stabilized Macadam with Early Strength Agent under Variable Temperature and Humidity Curing Conditions

作　　者：葛冬冬 刘定远 吕松涛[1,2,3] 姜向阳 薛艳华 于洋 GE Dongdong;LIU Dingyuan;LYU Songtao;JIANG Xiangyang;XUE Yanhua;YU Yang(College of Transportation Engineering,Changsha University of Science&Technology,Changsha,Hunan 410114,China;National Engineering Research Center of Highway Maintenance Technology,Changsha,Hunan 410114,China;National Key Laboratory of Green and Long-Life Road Engineering in Extreme Environment(Changsha),Changsha,Hunan 410114,China)

机构地区：[1]长沙理工大学交通学院,湖南长沙410114 [2]公路养护技术国家工程研究中心,湖南长沙410114 [3]极端环境绿色长寿道路工程全国重点实验室(长沙),湖南长沙410114

出　　处：《中外公路》2025年第1期31-41,共11页Journal of China & Foreign Highway

基　　金：国家自然科学基金资助项目(编号:52108398)。

摘　　要：在大温差、低湿度环境下,水泥稳定碎石的养生条件不能满足规范要求,导致其早期强度增长缓慢,容易产生开裂。该文旨在探讨工程实际环境温度、湿度、养生龄期以及早强剂掺量对水泥稳定碎石断裂性能的影响。根据实际环境气温数据确定变温条件,并以不同温度(变温和标准温度)和湿度(相对湿度95%、80%、65%)条件的组合设置4种养生条件。按照0%、10%以及15%的早强剂掺量制备3种试件,分别养生14 d和28 d。通过劈裂强度试验、四点弯曲弯拉强度试验、四点弯曲弯拉模量试验和半圆弯曲试验对试件的断裂性能进行测试。结果表明:在变温条件下,水泥稳定碎石的断裂性能包括强度、刚性和韧性均低于标准温度条件。其中劈裂断裂功下降幅度最大,为31.74%,弯拉模量最小,为8.60%;湿度越低,水泥稳定碎石断裂性能越差;掺早强剂可以缓解养生条件的负面影响;通过扫描电子显微镜观察到,变温或者较低湿度会使水泥水化程度降低,而掺早强剂使其升高;通过相关性和可靠性分析,建议使用四点弯曲试验来测试水泥稳定碎石的断裂性能。In environments with large temperature variations and low humidity,the curing conditions of cement-stabilized macadam fail to meet the specifications,leading to slow early strength development and increased susceptibility to cracking.This study aimed to investigate the effects of actual environmental temperature,humidity,curing age,and addition of early strength agents on the cracking characteristics of cement-stabilized macadam.Variable temperature conditions were determined based on actual environmental temperature data.Four curing conditions were set by combining temperatures(variable temperature and standard temperature)with relative humidity of 95%,80%,and 65%,respectively.Three types of specimens were prepared with 0%,10%,and 15%early strength agent contents and cured for 14 and 28 days,respectively.The cracking characteristics of the specimens were evaluated through splitting tensile strength tests,four-point bending flexural strength tests,four-point bending flexural modulus tests,and semi-circular bending tests.The results show that under variable temperature conditions,the cracking characteristics of cement-stabilized macadam,including strength,rigidity,and toughness,are lower than those under standard temperature conditions.Among them,the decrease in splitting fracture work is the most significant at 31.74%,while the reduction in flexural modulus is the smallest at 8.60%.Lower curing humidity indicates an increased susceptibility of cement-stabilized macadam to cracking.The incorporation of early strength agents can mitigate the negative effects of curing conditions.Scanning electron microscope(SEM)observations reveal that variable temperature or lower humidity reduces the degree of cement hydration, while the addition of early strength agents enhances it. Based on correlation and reliability analysis, the four-point bending test is recommended for assessing the cracking characteristics of cement-stabilized macadam.

关 键 词：水泥稳定碎石 断裂性能 早强剂 变温变湿养生 相关性分析 

分 类 号：U414[交通运输工程—道路与铁道工程]