ENHANCING FIRE RESISTANCE OF Gmelina arborea USING SODA ASH AND BORIC ACID ADMIXTURE

Abstract

The timber used in construction is often susceptible to combustion during fire outbreaks, necessitating the enhancement of its flame-retardant properties. In this study, Gmelina arborea was impregnated with boric acid, soda ash, and their admixture to assess fire resistance properties. The treated wood was characterized using thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), while key operational parameters – ignition time (IT), flame propagation rate (FPR), and after-glow time (AGT) – were evaluated. The percentage residue for boric acid was 68.8%, for soda ash 68.3%, and for the admixture 8.60%, indicating the highest ignition time for the admixture-treated sample. SEM analysis revealed that the micrographs of soda ash and boric acid treatments exhibited rough and undefined structures compared to the well-defined pores of the admixture-treated wood, highlighting structural modifications that enhance fire resistance. The results demonstrated that soda ash, boric acid, and their admixture effectively delayed ignition and reduced flame spread. The combined admixture exhibited the highest fire resistance, lowest flame propagation rate, and shortest after-glow time. Notably, while individual treatments improved fire resistance, their combination at varying concentrations displayed a synergistic effect, further enhancing the material’s fire retardancy.

Keywords: Boric acid, Fire resistance, Gmelina arborea, soda ash.