Investigation on the use of reclaimed asphalt pavement along with steel fibers in concrete

Abstract

Poor disposal and handling of asphalt material in construction activities has a great effect on the environment. Despite the use of asphalt material in other activities, a high percentage of it is poorly handled in Uganda. For this, the present study aimed to investigate the mechanical performance of reclaimed asphalt pavement (RAP) along with steel fibers in concrete and the variation of mechanical behavior concerning different curing times with the optimal RAP aggregate-substitute ratio. The result showed that the mechanical and physical properties of the fine and coarse aggregates used suited the replacement when compared with BS EN standard. Workability of fresh concrete is reduced as the percentage RAP increases in the mixture. This reduction was caused due to the asphalt mortar coating on the RAP aggregates, dirt particles and the irregular shape of aggregates. The compressive strength increases and decreases afterward with the increase of the percentage RAP replacement ratio. This occurred due to the presence of oils in the bitumen and weak bond between the asphalt binder coating around the RAP aggregates. When the steel fibers increase, the split strength increases along with curing time. A maximum savings of 6.13% of RAP was accomplished by incorporating 60% RAP replacement mix. For the Uganda scenario, this work serves as a guide for excess RAP application in construction activities. Using reclaimed asphalt materials provides a long-term solution for reducing the cost of materials and end-of-life materials disposal in the landfill.