摘要
再生沥青混合料中因含有沥青混合料回收料(RAP)和再生剂,其高低温性能往往难以控制或评价。为此,利用三轴重复压缩蠕变试验和直接拉伸松弛试验测定了不同混合料的高温指标(永久变形ε_(p)与其对应的流变次数F_(N))和低温指标(松弛时间t_(s)),进而分析了不同RAP掺量(20%,30%,50%)、油石比和再生剂掺量对再生沥青混合料高温蠕变和低温松弛性能的影响。结果表明:采用ε_(p)/F_(N)和t_(s)可以分别有效评价再生沥青混合料的高温蠕变和低温松弛性能。对于高温蠕变性能而言,当再生剂掺量和油石比一定时,随着RAP掺量的增大,再生沥青混合料的ε_(p)/F_(N)减小,即高温蠕变性能变好,当RAP掺量一定时,高温蠕变性能则随着再生剂掺量或油石比的增大而变差;对于低温性能而言,当再生剂掺量和油石比一定时,随着RAP掺量的增大,再生沥青混合料的t_(s)增大,即低温松弛性能变差,当RAP掺量一定时,低温松弛性能则随着再生剂掺量或油石比的增大而变好,且RAP掺量越大,再生剂和原样沥青对低温松弛性能的改善效果越明显。此外,由ε_(p)/F_(N)和t_(s)这2个指标的变化值可知,再生剂比原样沥青具有更好的再生效果。研究结果可为再生沥青混合料的耐久性能改善、生产和应用提供参考。
Due to the presence of reclaimed asphalt pavement(RAP)and recycling agent in recycled asphalt mixture,its high and low temperature performance is often difficult to be controlled or evaluated.Therefore,the high-temperature indicators(permanent deformationε_(p) and its corresponding rheological number F_(N))and lowtemperature indicator(relaxation time t_(s))of different recycled asphalt mixtures are determined by triaxial repeated compression creep test and direct tensile stress relaxation test.Then,the influences of different RAP contents(20%,30%,50%),asphalt-aggregate ratios,and rejuvenator contents on the high-temperature creep and lowtemperature relaxation performance of recycled asphalt mixture are investigated.The result shows that(1)the high-temperature creep and low-temperature relaxation performance of recycled asphalt mixture can be evaluated effectively byε_(p)/F_(N) and t_(s).For high-temperature creep performance,when the rejuvenator content and asphaltaggregate ratio are constant,with the increase of RAP content,theε_(p)/F_(N) of recycled asphalt mixture decreases,i.e.,the high-temperature creep performance improves.When the RAP content is constant,the high-temperature creep performance deteriorates with the increase of rejuvenator content or asphalt-aggregate ratio.(2)For lowtemperature performance,when the rejuvenator content and asphalt-aggregate ratio are constant,the lowtemperature relaxation performance improves with the increase of rejuvenator content or asphalt-aggregate ratio.The higher the RAP content,the more obvious the influence of the rejuvenator and virgin asphalt on the lowtemperature relaxation performance of the mixture.In addition,the variations ofε_(p)/F_(N) and t_(s) indicate that the rejuvenator has better regeneration effect than the original asphalt.The study result can provide reference for the improvement of durability performance,production and application of recycled asphalt mixtures.
作者
李雪连
许杰
叶峻宏
王随原
张显安
LI Xue-lian;XU Jie;YE Jun-hong;WANG Sui-yuan;ZHANG Xian-an(School of Traffic and Transportation Engineering,Changsha University of Science and Technology,Changsha Hunan 410114,China;Guangdong Communications Planning&Design Institute Group Co.,Ltd.,Guangzhou Guangdong 510503,China;China Road and Bridge Co.,Ltd.,Beijing 100011,China;Hubei Traffic Engineering Testing Center Co.,Ltd.,Wuhan Hubei 443000,China)
出处
《公路交通科技》
CSCD
北大核心
2023年第8期9-15,共7页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(52178412)。
关键词
道路工程
蠕变与松弛
三轴重复压缩蠕变试验
直接拉伸松弛试验
再生沥青混合料
耐久性
road engineering
creep and relaxation
triaxial repeated compression creep test
direct tensile relaxation test
recycled asphalt mixture
durability
