The effect of granulated blast-furnace slag on some technological properties of cement-bonded particleboard

THE EFFECT OF GRANULATED BLAST-FURNACE SLAG ON SOME TECHNOLOGICAL PROPERTIES OF CEMENT-BONDED PARTICLEBOARD In this study, the possibilities of using ground granulated blast furnace slag (GGBFS), which is produced as waste in iron and steel factories, as a substitute for Portland cement in the production of cement-bonded particleboard were investigated. For this purpose, single-layer cement-bonded particleboards with 1/2-1/3 wood-cement ratio, 1200 g/cm³ target density, and 450x450x10 mm dimensions were produced by using GGBFS at different ratios (10%, 20%, 30%, 40%, 50% and 60%) as a substitute for Portland cement. Physical and mechanical tests such as humidity (TS EN 322), density (TS EN 323), water absorption (ASTM D1037), thickness swelling (TS EN 317), modulus of rupture (TS EN 310), modulus of elasticity (TS EN 310), screw holding resistance (TS EN 320) and internal bonding strength (TS EN 319) were performed on the produced boards, and the obtained results were compared with the relevant standard. The test results demonstrated that the moisture content values of the boards decreased with the increase of GGBFS substitution, while the density values increased up to 20% GGBFS substitution and decreased above this rate. The water uptake values for 2 and 24 hours were the lowest in the control boards, and the highest in the boards with 60% GGBFSsubstitution. The water absorption values of the boards with 1/2 wood-cement (WC) ratio were higher than the boards with 1/3 wood-cement (WC) ratio. The thickness swelling values of the boards also increased with the increase of GGBFS, especially in the 1/2 WC-ratio boards. The use of GGBFS up to 40% in the 1/3 WC-ratioboardsled to an increase in the bending strength values of the boards, while the bending strength values of the boards with 1/2 WC-ratio decreased with the increase of GGBFS. The substitution of GGBFS to cement up to 20% in 1/3 WC-ratio boards did not have a statistical effect on the flexural modulus of elasticity of the boards, but the flexural modulus of elasticity decreased with the use of GGBFS in 1/2 WC-ratio boards. The use of GGBFS, especially in the use of more than 30%, also caused a decrease in the screw-holding resistance of the boards. The use of GGBFSup to 30% did not have statistically a significant effect on the internal bond strength values of the 1/3 WC-ratio boards, but the internal bond strength values of the 1/2 WC- ratio boards decreased with the increase of GGBFS. Keywords: Granulated blast furnace slag, wood-cement ratio, cement-bonded particleboard, physical properties, mechanical properties