What should be the nominal thickness after rolling of bituminous mixture for hot mix asphalt concrete?

The nominal thickness after rolling of a bituminous mixture for hot mix asphalt concrete should be no more than 80mm per layer. This thickness is ideal because it provides a balance between achieving the necessary density and ensuring proper compaction of the asphalt. Thicker layers can lead to difficulties in achieving uniform compaction, which is critical for the performance and longevity of the pavement.

If the layer is too thick, it may not compact adequately, leading to issues such as poor surface quality, reduced durability, and potential deformation under load. Maintaining the nominal thickness at 80mm helps to ensure that the material can adequately dissipate heat during the rolling process, resulting in optimal performance characteristics of the asphalt layer once it has cooled. This thickness aligns with industry standards and practices for hot mix asphalt concrete pavement construction, promoting effective load distribution and extending the life of the surface layer.