Effects of fly ash on some properties of cemented particle boards

In this study; the effect of using fly ash in different proportions (5%, 10%, 15%, 20%) as a substitute for cement on the physical, mechanical and thermal properties of the produced cement-bonded particleboard was investigated. For this reason, single-layer cement-bonded particleboards with dimensions of 450x450x10 mm with a target density of 1200 g/cm3 were produced by using spruce planer waste, fly ash in different proportions, Portland cement, wood-cement ratio of 1:3 and 5% CaCl2 in order to eliminate wood-cement incompatibility. Moisture content, density, water absorption and thickness swelling, modulus of rupture and modulus of elasticity, internal bond strength, screw withdrawal strength, morphological properties (SEM) thermogravimetric (TGA) and derivative thermogravimetric analysis (DTG) of produced particleboards were determined and compared with control samples according to TS EN 634-1, TS EN 323, ASTM D1037, TS EN 317, TS EN 310, TS EN 319 and TS EN 320, respectively. The experimental results showed that fly ash slightly increased the humidity of the particleboards. It was determined that the density of the particleboards decreases as the amount of fly ash increases. It was observed that as the amount of fly ash usage increased in the test particleboards, the water absorption of these particleboards increased after 2 and 24 hours. However, as the amount of fly ash usage increased, the thickness swelling decreased after 2 and 24 hours. In general, all particleboards produced using fly ash gave higher modulus of rupture and modulus of elasticity than the control particleboard. On the other hand, it was observed that fly ash has a negative effect on the internal bond strength and screw withdrawal strength of the particleboards. Keywords: Fly Ash, Oriental Spruce, Cement-bonded particleboard, CaCl2, Physical and Mechanical Properties