新型小粒径沥青混凝土NAC-10的级配优化研究

Gradation Optimization of New Small Size Asphalt Concrete(NAC-10)

通过各档粗集料逐级填充试验,研究了公称最大粒径为9.5 mm的小粒径沥青混凝土的主骨架级配,提出了NAC-10的粗集料优化级配（9.5～13.2 mm∶4.75～9.5mm∶2.36～4.75 mm的质量比为17 ∶ 53 ∶ 30）;按照密级配填充理论和泰勒公式,计算得到粗细集料的质量比为3∶1和细集料各筛孔的通过量,并深入分析了细集料用量对粉胶比、沥青膜厚以及高温稳定性的影响,提出了细集料的优化级配.通过粗、细集料优化级配合成,提出了一种新型骨架密实小粒径沥青混凝土（NAC-10）的级配范围,并将NAC-10成功应用于坛百高速公路沥青混凝土路面的车辙修复工程,结果表明：NAC-10沥青混凝土的骨架密实性更强,最佳油石比低于AC-10沥青混凝土,空隙率更低,沥青饱和度更高,高温稳定性更好,而水稳定性与AC-10沥青混凝土大致相当.

This paper researches the small size asphalt concrete main skeleton gradation with the nominal maximum particle size of 9.5 mm through the various coarse aggregate gradually filling test, puts forward the NAC-10 coarse aggregate optimization grading （the mass ratio of 9.5--13.2 mm,4. 75-- 9.5 mm and 2.36--4.75 mm is equal to 17 ： 53 ： 30） ; according to the dense gradation filling theory and Taylor formula, the mass ratio of the coarse and fine aggregate is equal to 3 ： 1 and the fine aggregate throughput of each mesh, and analyses in-depth the effects of the fine aggregate amount on the powder cement ratio, asphalt film thickness and high temperature stability, thereby puts forward the fine aggregate optimization grading. Through the coarse and fine aggregate optimization level, the grading scope of a new skeleton dense small size asphalt concrete（NAC-10） is proposed, and the NAC-10 is successfully applied in the rutting rehabilitation engineering of the Tanbai highway asphalt pavement. The results show that skeleton-dense capability and high temperature stability of NAC-10 asphalt concrete is better than AC-10, and the pavement rutting is well treated.