Environmental impacts of MIBA in geotechnics and road applications

This paper assesses the environmental impacts of municipal solid waste incinerator bottom ash (MIBA) as a potential construction material in road pavements and geotechnical applications, through systematic analysis and evaluation of the global literature published in the English medium. The principal environmental concerns relate to the potential for leaching of the constituents contained in MIBA into surface and ground waters. MIBA is examined as an aggregate component in three application forms: unbound, hydraulically bound and bituminous bound. The evaluation of the papers concludes that the material is fit for use as an aggregate; however, standard ageing processing and at times washing treatments were considered necessary for the unbound form, where the possibility of contaminant release is the greatest. The presence of cement and bitumen as binder restricts the release of elements and alters the leaching behaviour from percolation to diffusion controlled. Concentrations released from both application types were below respective utilisation and water quality limits, suggesting that environmental impacts should not limit the potential use of MIBA in cement- and bituminous bound applications.