Evaluation of the Effective Factor On HMA Pavements Raveling

In the flexible pavements, Raveling of Hot Mix Asphalt (HMA) refers to the wearing down of the surface due to the combined effects of water and traffic. Pavements installed later in the construction season are more prone to this issue compared to those laid earlier, primarily because these mixtures often miss the beneficial effects of warm weather traffic, which helps reduce surface voids and promotes further densification. The resistance to raveling can significantly differ from one mixture to another, depending on various factors. This problem is commonly linked with late-season construction, cool ambient and base temperatures, and the presence of moisture combined with traffic impact. Variable factors that may contribute to raveling include the mix criteria, the temperature-viscosity relationship of the asphalt, the production process, compaction techniques, in-place air voids, and freeze-thaw cycles when moisture is present. Since weather conditions are beyond control, raveling might still occur despite following ideal specifications and construction practices. Successfully managing late-season paving involves being mindful of negative factors, making necessary adjustments, and mitigating associated risks. If raveling is suspected, it's wise to conduct a site review and closely monitor the project. It's important to avoid leaving loose material on the surface for long periods, particularly with ongoing traffic and the presence of water or moisture, as these conditions often worsen raveling. Before making any quick decisions, a field review later in spring is highly recommended. A cooperative approach will be crucial for resolving the issue, gaining project acceptance, and ensuring long-term performance if raveling occurs.

کلیدواژه ها:

Flexible Pavement Distress ، Raveling ، HMA ، Mix criteria