Use of Ashes from Biomass Combustion as an Aggregate for Concrete

This paper discusses an environmentally-friendly destination for the residual ashes resulting from the firing of biomass (wood wastes) at the Engie Brasil Cogeneration Power Plant located in Lages, Santa Catarina, Brazil. The study proposes reusing the residue as a substitution for crushed stones in the production of concrete. Environmental, physical, and chemical analyses were performed for characterization of the ashes. Specimens prepared with ash and subjected to testing presented a compressive strength of around 18.63 Mpa (2700 psi), which is in compliance with the ACI-213R and ASTM C330-5 specifications. With pretreatment and proper mixing ratios, biomass ashes may be employed as an aggregate in the manufacture of lightweight structural concrete.