Utilization of bottom ash on thin asphalt surfaced pavements for low volume roads

Abstract

More than 65% of the entire road network of Sri Lanka consists of low volume roads with AADT of 1000 vpd or less. The provision of better surfacing for these roads has become one of the main needs nowadays and traditional asphalt pavements are not recommended due to their higher layer thicknesses; thus, higher cost. Therefore, an adaptation of thin surfaced asphalt pavements can yield favorable solutions and this research was carried out to develop mixture design and check the suitability of utilizing bottom ash, to achieve durable, economical and sustainable thin asphalt pavements while reducing the environmental issues associated with the waste generated from the coal power plant. Marshall samples were prepared for DG 7 mixtures with the replacement of 0%, 10%, 20%, and 25% of fine aggregates with bottom ash. The Marshall properties of the specimens were examined and concluded that only DG 7 mixtures with 0% and 10% of bottom ash replacements attained the required Marshall criteria to be used in low volume roads. Even though the mixtures without bottom ash are determined as more economical, mixtures with 10% of bottom ash are recommended as the voids in mineral aggregates criteria were well established in them.