单粒径沥青混合料的级配研究

Study on Gradation of Single-particle Size Asphalt Mixtures

摘要:

为解决普通级配沥青混合料在半柔性材料应用中级配设计复杂的问题，通过适配性筛选与性能优化，对16.0~13.2、13.2~9.5、9.50~4.75 mm这3种单粒径级配沥青混合料的连通空隙率和马歇尔强度进行了协同分析。结果表明：最优单粒径级配为13.2~9.5 mm，其最佳油石比为5.0%，在此参数下，沥青混合料马歇尔强度可达4.2 MPa，超过《公路工程沥青及沥青混合料试验规程》要求40%；连通空隙率为35.3%，仅比上述规程要求的上限高18%，可同时满足半柔性材料对承载能力和灌浆适配性的需求。

Abstract:

To solve the problem of complex gradation design of common graded asphalt mixtures in semi-flexible material applications, a collaborative analysis is conducted on the connected void ratio and Marshall strength of three single-particle size gradated asphalt mixtures, namely 16.0~13.2 mm, 13.2~9.5 mm, and 9.50~4.75 mm through the compatibility screening and performance optimization. The result shows that the optimal single-particle size gradation is 13.2~9.5 mm, and its optimal asphalt-aggregate ratio is 5.0%. Under this parameter, the Marshall strength of the asphalt mixture can reach 4.2 MPa, exceeding the requirements of the Test Code for Asphalt and Asphalt Mixture in Highway Engineering by 40%. The connected void ratio is 35.3%, which is only 18% higher than the upper limit required by the above-mentioned code, and can simultaneously meet the requirements of semi-flexible materials for bearing capacity and grouting adaptability.