Assessing paver screed compaction units and their impact on asphalt quality parameters through field trials

Ensuring the durability and longevity of asphalt pavements under traffic loads requires effective compaction during paving to resist deformation and withstand environmental stresses. While previous field-based studies have addressed asphalt compaction and selected screed settings, this study specifically links tamper speed and vibratory unit speed to pre-compaction, vertical void distribution, aggregate structure, and 3D surface roughness under real paving conditions. Two field trials using an ABG P6820D paver and BOMAG BW 174 roller were conducted with an AC 16 BN asphalt mix. Laboratory analyses evaluated layer thickness, bulk density, cavity structure, and surface roughness. The findings highlight that tamper speed significantly influences layer thickness and degree of compaction, while vibratory unit speed showed no substantial effect. Vertical void distribution was highly homogeneous (> 98%) across pre-compacted areas, indicating tamper speed does not affect void distribution. Surface roughness tended to decrease with increased tamper speed, but vibratory unit speed showed no measurable benefit. No significant correlation was found between grain-to-grain distance or microstructural properties and vibratory unit speed. The study recommends minimizing adjustments to tamper speed during paving and suggests switching off the vibratory unit for the investigated AC 16 BN mixture under comparable paving conditions, provided that the required pre-compaction and surface quality are achieved. Regular monitoring of tamper wear and precise pre-paving adjustments are essential to enhance pavement quality and reduce maintenance costs.