Potential use of biomass bottom ash as alternative construction material: Conflictive chemical parameters according to technical regulations

The production of energy from renewable resources, such as biomass, is increasing rapidly. Therefore, environmentally friendly and economic solutions to recycle the resulting by-products are essential. The present study was performed to search for possible applications of the biomass bottom ashes that result from biomass combustion at three biomass combustion plants located in the Andalusia region of southern Spain. The analysis of chemical parameters indicated the applicability of biomass bottom ashes as an alternative material in civil construction. Thus, the limiting chemical parameters were analysed according to Spanish regulations. According to the results, biomass bottom ashes could be used as filler in road embankments, cement-treated materials or non-structural concrete, depending on the replacement percentage. This study determined that a review of the chemical parameters specified by the limiting regulations is recommended to promote the use of biomass bottom ashes as a building material in applications that do not require high structural strength.