Effect of wood particle geometry and pre-treatments on the strength and sorption properties of cement-bonded particle boards

Abstract

The effect of particle geometry and pretreatments on the strength and sorption properties of wood particle cement composite boards was investigated. Wood particles (flakes and sawdust) of Gmelina arborea were mixed with cement and water in the production of composite boards. The wood particles were pretreated with hot water, calcium chloride and a combination of both treatments to enhance bonding with cement. The slurry was poured into rectangular moulds for board formation. After demoulding, the boards formed were tested for modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA) and thickness swelling (TS). The results revealed that the mean MOR for flakes boards was 3.23N mm-2 while the mean MOR for sawdust boards was 3.01N mm-2. Hot water and calcium chloride treatment produced the best effect in flake composite boards with MOR and MOE values of 6.90 N/mm2 and 1897.36 N mm-2 while sawdust composite boards had mean MOR and MOE values of 5.69N mm-2 and 1664.31N mm-2 respectively. The WA rate after 24 hours of flakes and sawdust boards treated with hot water and calcium chloride was 3.63% and 4.28% while the TS rate was 0.69% and 1.44% respectively. Particle geometry and pretreatments significantly improved strength and sorption properties of wood particle cement composite boards (p<0.05).