Cement type composite panels manufactured using paper mill sludge as filler

The aim of this study was to evaluate some physical and mechanical properties of the paper mill (PMS) and spruce planer shaving added cement boards. Also the effect of sludge type in consequence of waste water treatment technique on properties of wood-cement boards (WCB) was investigated. The wood/cement ratios were used as 1/3, based on the oven dry weight for the WCB manufacture. PMS was used up to 20% wt of total composite based on organic (wood) and inorganic (cement) amounts. Black sludge has shown more improvement than grey sludge on properties of WCBs, which indicates the anaerobic waste treatment technique is more effective for additive in WCB. The modulus of rupture and elasticity values of the WCBs with 5% of grey sludge, 5% and 10% of mixture of grey and black sludge were acceptable limits according to EN 634-2 standard. The mechanical strengths of all WCBs with black sludge were found above the specified EN standard. This suggests that PMS depending on sludge type may be used up to 20% wt of total composite weight for the commercial production of WCBs, which could expand the raw material base for this panel product.