Recycling of fine-asphalt-pavement solid waste for low-shrinkage rapid hardening Portland cement concrete pavement

Abstract This study aims to investigate the effects of using fine reclaimed asphalt pavement (RAP) and fly ash (FA) on the mechanical and shrinkage behaviors of rapid hardening Portland cement (RHPC) concretes. Thus, several tests were carried out to assess the engineering properties of the original fine RAP. Using the orthogonal design method, mechanical tests were conducted to evaluate the effects of cement dosage, water-to-cement ratio (W/C), RAP content, and FA content. In addition, the influence of the RAP and FA on the shrinkage properties was estimated via shrinkage tests. The results indicate that the W/C was the most significant factor affecting the fresh and mechanical properties. With partial replacement (0–25%) of cement and sand by FA and RAP, the strength data suggested the possibility of completing road reconstruction 21 d in advance. Moreover, minor differences in the thermal expansion coefficient were observed for the combined use of RAP and FA. Instead, increasing the percentage of FA and RAP contributed to improved dry and plastic shrinkage behaviors. These results confirm the possibility of achieving more rapid recovery, sustainability, and higher-cracking-resistant pavement concrete.