透水型尾气降解沥青混合料性能评价

Performance evaluation of water permeable type tail gas degradation asphalt mixture

为研究透水功能对沥青混合料尾气降解性能的影响,研发透水路面光催化降解尾气测试系统,提出基于光降解试验确定TiO_2掺配方式、粒径和掺量的方法。建立基于连通空隙率的降解性能回归模型,定量分析静态饱水率和动态透水过程对尾气降解效果的影响。研究结果表明:在OGFC-16级配条件下,采用湿法工艺,TiO_2粒径为25 nm,掺量为沥青质量10%时降解效果最优。除100%的饱水率,其他各级饱水率下累积降解率的排序为TAC-16>OGFC-16>AC-16,累积降解率随饱水率升高而下降;动态透水阶段累积降解率先缓慢升高后快速升高,最后趋于稳定,全过程累积降解率排序为TAC-16>OGFC-16>AC-16,推荐透水型大孔隙级配作为尾气降解混合料载体;基于混合料降解效果和水稳定性,建议连通空隙率越大越好,但不超过18.7%。

In order to study the influence of water permeability function on tail gas degradation performance of asphalt mixture, Test system for permeable type photocatalytic degradation of exhaust gas was developed. A regression model of degradation performance based on connected void fraction was established, quantitative analysis of the effects of static saturation rate and dynamic permeability on the degradation of tail gas was conducted. The research shows that： under the OGFC-16 grading condition, the degradation effect is best, when the particle size of TiO2 is 25 nm, the content is 10%, and taking the wet process. At all the levels of saturation rate out of 100%, the cumulative degradation rate is TAC-16〉OGFC-16〉AC-16, the cumulative degradation rate decreases with increasing of water saturation; In the dynamic permeability stage, cumulative degradation takes the starts to increase slowly and then rapidly, at last, it tends to be stable, the cumulative degradation rate is TAC-16〉OGFC-16〉AC-16 inf the whole process, Permeable type macropore gradation is recommended as the tail gas degradation mixture carrier. Based on the degradation effect of the mixture and water stability, it is suggested that the bigger the relative void fraction is, the better, but not more than 18.7%.