Optimum Ratio of Lignite Bottom Ash and Rock Dust in Asphalt concrete

Abstract

This research focused on asphalt concrete using lignite bottom ash and rock dust as mineral dust in the mixture. Bottom ash is the coalesced waste residue from lignite burning in power generation. In this study the material was obtained from Mae Moh Themal Plant, Lampang Province. Two types of aggregate were used, limestone and basalt. The proportions of bottom ash and rock dust were determined from hot bin 1 by trial and error. Asphalt content, by weight of aggregate, varied from 4.5-7.5% for limestone and 5.5-8.5% for basalt, determine the optimum asphalt content. The results indicated that for limestone, the optimum ratio of bottom ash to rock dust was 0.043. Optimum percentage of bottom ash and asphalt were found to be 2% and 6.2% by weight of aggregate respectively. For basalts, The results indicated that the optimum ratio of bottom ash to rock dust was 0.042. Optimum percentage of bottom ash and asphalt were found to be 2% and 7.2% by weight of aggregate respectively. It was noted using bottom ash resulted in increasing demand for asphalt for both aggregates. This cost increase must be considered in according with the benefit of waste utilization.