Abstract:

In this study, it was found that the addition of wood had a reducing effect on water absorption (WA) and thickness swelling (TS) properties in gypsum-based boards. The lowest WA value of 41.56% was found sample prepared with cedrus’s bark/needle mixture (KaI3; 3:2 by weight). It has also been realized that experimental boards made only bark-gypsum (SKa6), cone-gypsum (SKo6) and needle-gypsum (SI6) proportions show Thickness Swelling (TS) values of 33.70%, 21.70% and 18.85%, respectively. However, the surface hardness (Shore D) has usually correlated with wood content but natural weathering negatively effects hardness that lowering from -6.9% (SKa1) to -30.3% (SKa2) in all typse experimental boards. It was found that panels produced with cedrus wood/cone (SKo); cedrus wood/needle (SI) and cedrus cone/needle (KoI) proportions have no higher values than standard Internal Bond (IB) value of 0.28 N/mm2. But the highest IB value of 0.48 N/mm2 was observed for a sample of SKa5 that produced with a ratio of 1:4 by cedrus wood/bark proportions (w/w). Moreover, the highest bending strength (MOR) values of 1.32 N/mm2 were calculated with SKa2 sample that produced with ratio of 4:1 by cedrus wood/bark proportions (w/w). These mechanical properties are probably related to experimental board manufacturing process, which consists of multi stage processing (slushing, soaking, formation, pressing and drying) may effect hindering reinforcement elements to develop the network matrix strength properly.

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