Estabilidade térmica e reação ao fogo do bio-concreto de madeira

Abstract

Wood bioconcretes(WBC) are presented as a solution for the advancement of sustainable construction, since they allow the reuse of waste generated in the wood processing and store biogenic carbon inside. However, the behavior of this material under high temperatures and its reaction to fire properties are barely known. This work aims to evaluate the thermal stability of WBCs and to submit them to temperatures ranging from 22 ºC to 250 ºC, as well as to evaluate their reaction to fire properties. Density, compressive strength and scanning electron microscopy tests were performed in WBCs with biomass contents of 40, 50 and 60%, before and after submitting the variables to high temperatures. Thermal conductivity tests were performed on the same mixtures only at room temperature. Alkaline and thermal treatments were studied in the biomass to guarantee the resistance gain of the bioconcrete over time, with the immersion of the biomass in Ca(OH)2 solution in two cycles being more efficient. The mass loss cone calorimeter was used to analyze the combustion and fire reaction properties of WBC with biomass contents ranging from 40 to 70%. The thermal conductivity, density and compressive strength of bioconcrete gradually decreased with an increase in the biomass content. Up to 200 ºC, reductions in strength and densities of less than 19% and 13%, respectively, were observed. At 250 ºC, reductions in mechanical properties reached 87%. Despite using up to 70% volumetric biomass fractions, bioconcretes did not present ignition