The large-stone asphalt mixture is a promising approach to improve rutting resistance of roads under very heavy traffic. This paper describes the rehabilitation of two test sections in Brazil using a composite of dense graded asphalt mixtures with typical (9.5 or 19 mm) and large-stone (32 mm) nominal maximum aggregate size to decrease rutting while simultaneously preserving the functional surface qualities of the pavement. The asphalt mixtures used in this study were characterized for their linear viscoelastic properties using dynamic modulus and rutting resistance using the French wheel tracking test. The rehabilitated pavement was monitored over a period of 2 years and demonstrated minimal rutting. This was in contrast to the 12–15 mm rutting that occurred over just 1 year prior to the rehabilitation when only 9.5- and 12.5-mm size dense graded mixture was used on the surface with different asphalt binders. This study also demonstrates that this difference in field performance was not reflected when using viscoelastic layered analysis of the pavement structure, which is a recognized limitation when damage analysis is not considered.

A aplicação de material asfáltico fresado (RAP) para obras rodoviárias e intervenções restaurativas tem sido crescente diante da necessidade de reduzir a geração de resíduos, por meio da reutilização, e aumentar a circularidade na construção civil. O objetivo deste estudo é avaliar o potencial benefício ambiental da restauração de pavimentos com camada de mistura asfáltica reciclada a frio (MARF) com emulsão asfáltica, em comparação à restauração apenas com materiais virgens. Foram analisados os indicadores de consumo de material e de água, geração de resíduos sólidos e pegada de carbono. Os resultados apontam que a estrutura com material reciclado a frio tem melhores indicadores de circularidade em relação ao consumo de material e geração de resíduo, porém ela pode ter maior pegada de carbono que a estrutura flexível convencional. No entanto, as respostas de pavimento se diferenciam significativamente com potencial diferença de durabilidade entre as estruturas, atribuindo benefício ambiental à estrutura de pavimento reciclado (RECRap).

Heavy traffic and high temperatures are a common cause of rutting in paved areas, which reduces the time needed between pavement maintenance interventions. Large-stone asphalt mixtures (LSAMs) can reduce rutting when used as intermediate layers in pavement rehabilitation. LSAM is asphalt concrete with a nominal maximum aggregate size of at least 25 mm. In this study, we provide a brief literature review of the historical use of LSAMs, as well as the relevant characteristics of LSAM design. Three LSAMs were designed using different compaction methods: (i) Marshall compaction; (ii) rolling compaction; and (iii) Superpave gyratory compaction (SGC) by varying the compaction energy in 75, 100, and 125 gyrations. Depending on the mix design method used, the designed asphalt content ranged from 3.0 to 4.3%. The locking point from the SGC was evaluated at different gyratory compaction energies, which were related to the porosity of the dominant aggregate size range. These parameters are considered to be of great value when evaluating the LSAM design.