基于发泡技术的就地热再生沥青路面压实特性研究

Research on Compaction Characteristics of Hot In-place Recycling Asphalt Pavement Based on Foaming Technology

将泡沫温拌技术(FWMA)应用到就地热再生技术(HIR)中以改善就地热再生沥青混合料(HIR-AM)的压实效果。通过膨胀率和半衰期试验确定了泡沫沥青制备的工艺参数,研究了泡沫沥青对HIR-AM压实质量的提升效果,通过室内试验评价了泡沫就地热再生沥青混合料(HIR-FAM)的路用性能,最后结合实体工程对研究结果进行了验证,并总结了HIR-FAM施工工艺。研究结果表明:发泡温度为170℃、用水量为1.7%时,SBS改性沥青的发泡效果最佳;在相同的拌和温度下,FWMA可使HIR-AM空隙率降低3.8%~21.2%,能量压实度指数CEI降低27.83%~64.75%;动稳定度、弯拉强度、最大弯拉应变、残留稳定度和冻融劈裂强度比分别提高12.2%、13.4%、11.8%、8.8%、4.9%,且具有更好的水热稳定性。实体工程检测结果表明,采用HIR-FAM路段的平均压实度比采用HIR-AM的路段提高了0.79%以上,且其压实均匀性更优。

The foam warm mixing technology(FWMA) was applied to the hot in-place recycling technology(HIR) to improve the compaction effect of hot in-place recycling asphalt mixture(HIR-AM).The process parameters of foam asphalt preparation were determined through the expansion rate and half-life tests to study the improvement effect of foam asphalt on HIR-AM compaction quality.The road performance of foam geothermal recycled asphalt mixture(HIR-FAM) was evaluated through laboratory tests.Finally,the research results were verified by the physical project,and the HIR-FAM construction technology was summarized.The research results indicate that the foaming effect of SBS modified asphalt is optimal when the foaming temperature is 170 ℃ and the water consumption is 1.7%;At the same mixing temperature,FWMA can reduce the porosity of HIR-AM by 3.8% to 21.2% and the energy compaction index CEI by 27.83% to 64.75%;The dynamic stability,flexural tensile strength,maximum flexural tensile strain,residual stability,and freeze-thaw splitting strength ratio have increased by 12.2%,13.4%,11.8%,8.8%,and 4.9%,respectively,and have better hydrothermal stability;Compared with the HIR-AM section,the results of the actual engineering inspection show that the average compaction degree of the HIR-FAM section has increased by more than 0.79%,and its compaction uniformity is better.