摘要
为了研究建筑垃圾再生骨料在水泥稳定碎石中的适用性,采用冲刷试验、干湿循环试验、冻融循环试验和劈裂疲劳试验,研究了掺再生骨料水泥稳定碎石混合料(CACSM)在环境荷载作用下的性能劣化规律。明确了冲刷时间、干湿循环次数和冻融循环次数对CACSM力学强度的影响。分别构建了CACSM在不同条件下的性能劣化预测模型,提出了在环境荷载作用下CACSM强度劣化的极限值和疲劳寿命。结果表明:CACSM在水冲刷作用下损失质量随再生细集料掺量增大而增加,随冲刷时间延长先迅速增加后趋于稳定;干湿循环和冻融循环作用下CACSM具有明显的强度劣化效应,建立的强度劣化模型可以预估CACSM的强度劣化极限值;因再生集料的多孔结构和强吸水性导致CACSM在干湿及冻融循环过程中抵抗荷载的能力降低,CACSM的最低干湿极限劣化系数和冻融极限劣化系数分别为84.1%和63.5%;掺45%再生骨料细集料的CACSM的疲劳寿命略高于水泥稳定碎石,这表明适量掺加再生骨料细集料不会降低水泥稳定碎石抵抗荷载重复作用的能力;高再生骨料掺量的CACSM在环境荷载作用下性能劣化严重,在实际工程应用中须验证力学强度劣化极限值是否满足路面基层的要求。
To investigate the applicability of construction waste recycled aggregate in cement-stabilized macadam,this study adopted the scouring tests,wet-dry tests,freeze-thaw tests,and splitting fatigue tests to examine the performance degradation rules of recycled aggregate cement-stabilized macadam(CACSM)under environmental loads.The influences of scouring time,wet-dry cycles,and freeze-thaw cycles on CACSM mechanical strength were clarified.The performance degradation prediction models for CACSM under different conditions were constructed.The degradation limits and fatigue life of CACSM under combined environmental loads were proposed.The result indicates that the mass loss of CACSM under water scouring increases with a higher content of recycled fine aggregate.After an initial rapid increase,the mass loss tends to stabilize with extended scouring time.CACSM exhibits the significant strength degradation under wet-dry effect and freeze-thaw effect.The CACSM ultimate strength degradation can be accurately predicted with the degradation models.Due to the porous structure and high water absorption of recycled aggregate,CACSM’s load-bearing capacity decreases during wet-dry and freeze-thaw cycles with the minimum degradation coefficients of 84.1%and 63.5%respectively.Additionally,CACSM with 45%recycled fine aggregate shows a slightly higher fatigue life than that with cement-stabilized macadam,indicating that an appropriate amount of recycled fine aggregate will not compromise the ability of cement stabilized macadam to resist the repeated loading.CACSM with high recycled aggregate content experiences considerable degradation under environmental loads.In actual engineering applications,it is necessary to verify whether the limit value of mechanical strength degradation meets the road base requirements.
作者
蒋应军
张宇
易勇
范江涛
田甜
JIANG Ying-jun;ZHANG Yu;YI Yong;FAN Jiang-tao;TIAN Tian(Key Laboratory of Ministry of Education for Highway Engineering in Special Region,Chang’an University,Xi’an,Shaanxi 710064,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2024年第11期66-77,共12页
Journal of Highway and Transportation Research and Development
基金
交通运输行业重点科技项目(2021-MS1-011)
陕西省创新能力支撑计划项目(2022TD-06)
长安大学中央高校基本科研业务费专项(300102213401)。
关键词
道路工程
性能劣化预测模型
劈裂疲劳试验
水泥稳定碎石
建筑垃圾再生骨料
road engineering
performance degradation prediction model
splitting fatigue test
cement-stabilized macadam
construction waste recycled aggregate
