温拌再生沥青混合料的温度控制方法及路用性能

Temperature control method and road performance of warm mixed reclaimed asphalt mixture

为解决温拌再生沥青混合料(WMRA)设计与施工过程中的温度控制问题,提出了掺入Sasobit的WMRA的拌和与成型温度、新集料加热温度的确定方法,对WMRA和热拌再生沥青混合料(HMRA)进行Marshall试验、浸水车辙试验、低温弯曲试验和水稳定性试验,对比分析WMRA和HMRA的空隙率(VV)和路用性能。研究结果表明:提出的方法能够准确计算WMRA的拌和温度、成型温度和新集料加热温度;当再生利用废旧沥青路面材料(RAP)掺配比例较小且降低13℃成型时,WMRA与HMRA具有接近的空隙率,说明Sasobit的降温幅度约为13℃,能提高RAP的掺配比例近10.3%;与HMRA相比,WMRA具有更优的高温稳定性,具有相近的低温弯曲应变、残留稳定度和冻融劈裂强度比;WMRA和HMRA高温稳定性和低温抗弯拉强度均随着RAP比例的提高而增加,而低温弯曲应变、残留稳定度和冻融劈裂强度比均随着RAP比例的提高而降低。

This paper is aimed to solve the temperature control problem of warm mixed reclaimed asphalt mixture （WMRA） in the process of design and construction. A method was proposed for determining the mixing and compaction temperature of WMRA blending with Sasobit, and also for heating temperature of the new aggregates. The laboratory experiments including Marshall test, soaking rutting test, low temperature bending test and water stability test were utilized for analyzing the air void （VV） and road performance. The results show that the mixing and compac- tion temperature and heating temperature of new aggregates can be accurately determined by the proposed method for WMRA. The VV of WMRA compacted at the temperature lower than 13 ℃is approaching to HMRA when the proportion of RAP is much smaller, which indicates the Saso- bit can reduce compaction temperature by 13 ℃, and significantly improve the blending ratio of RAP by 10.3%. WMRA has better high-temperature stability than HMRA, and the low-temper- ature bending strain, residual stability degrees and TSR are approximately equal between WMRAand HMRA. The high-temperature stability and low-temperature flexural tensile strength of WMRA and HMRA increase as the RAP increases, but the low-temperature bending strain, re- sidual stability degree and TSR decrease. 9 tabs, 7 figs, 12 refs.