RECICLAGEM DE CINZAS DA COMBUSTÃO DA BIOMASSA FLORESTAL COMO MATÉRIA-PRIMA PARA ARGAMASSAS

Rendering mortars were prepared by replacing conventional sands, namely coarse sand (CS) and fine sand (FS), by different dosages of biomass dry bottom ash (BA) and fly ash (FA). Bottom ash was treated by sieving and washing and called treated bottom ash (TBA). All these ashes were characterized, and their effects on the physical and mechanical characteristics of mortars were studied. The dosage of water required to maintain workability of samples formulated with TBA, BA, and FA was not significantly different from the volume used to formulate a reference mortar, since the physical characteristics of the ashes used were similar to those of CS and FS. Workability, weight variation, unrestrained shrinkage and compressive strength were measured. The results showed that the pre-processing of BA and FA has to be properly characterized in the effort to reuse these materials as effective replacements of natural sand in mortars, and the associated environmental aspects should be further investigated to support this recycling strategy.