Sustainable Utilization of MSWI Bottom Ash as Road Construction Materials, Part I: Physical and Mechanical Evaluation

Abstract

Current management practice, existing regulations, and environmental consequences of municipal solid waste incineration (MSWI) ash utilization were comprehensively reviewed. Efforts were made to physically and mechanically characterize MSWI bottom and fly ashes and also to evaluate their influence on the structural properties of Portland cement concrete (PCC) and hot-mix asphalt (HMA) when part of fine aggregate is replaced with the MSWI bottom ash. Fundamental properties of MSWI bottom ash and fly ash were studied by conducting physical, microstructural, and chemical tests. Concrete cylinders were cast with various amounts of ash additions and their strength and durability were investigated as the replacement ratio of ash increases. The MSWI bottom ash was also used to replace fine aggregate in HMA. Varying proportions of bottom ash and fine aggregate were tried in an effort to determine the optimum ratio of bottom ash to fine aggregate, as determined by performance tests such as the Marshall Stability and Flow test and the moisture susceptibility test.