| This study aimed at the subsistent problems of heavy and poor interface compatibility between fiber and cement. Cement-based fiber composites were produced by cold press process using wood fiber and early-strength sulphoaluminate cement as raw materials, and wood fiber and additive effects on cement-based composites were studied. In addition, from the perspective of fiber pretreatment, effect of fiber morphology and beating degree of Eucalyptus pellita F. V. Muell. and Larix gmelini(Rupr.)Rupr. chemical plup on the composite were investigated. The studies draw the following conclusions:(1) Water-cement ratio and wood fiber content were the main factors that affected the density and bending strength;(2) Adding an appropriate amount of wood fiber can improve the bending strength of composite, but too much will reduce it;(3)Adding foam had significant effect on the density and water absorption, and adding polystyrene particles had significant effect on the density, bending strength and compressive strength;(4)Obtained by the single factor analysis of variance: beating degree of Eucalyptus pellita F. V. Muell. chemical pulp had significant effect on water absorption and density, no significant effect on the 24-hour thickness swelling and bending strength. the beating degree of Larix gmelini(Rupr.)Rupr. chemical pulp had significant effect on water absorption,density and bending strength, no significant effect on the 24-hour thickness swelling;(5)When cement was reinforced by Eucalyptus pellita F. V. Muell. chemical pulp, water absorption and long-width ratio increased first and then decreased, and the density of composites decreased first and then increased with the increasing beating degree. When the length-width ratio was 66.5, and beating degree is 23°SR, the composite had maximum strength weight ratio. At this time, the composite had the best overall performance, the density 1.19 g/cm~3, the moisture content 16.8%, bending strength 2.98MPa, 24h thickness swelling 0.277%;(6) When cement was reinforced by Larix gmelini(Rupr.)Rupr. chemical pulp, water absorption increased first and then decreased, long-width ratio,density and bending strength decreased first and then increased. When the length-width ratio was 93.7, and beating degree is 25°SR, the composite had maximum strength weight ratio. At this time, the composite had the best overall performance, the density 1.13 g/cm~3, the moisture content 14.1%, bending strength 2.83MPa, 24h thickness swelling 0.821%;(7)When cement was reinforced by chemical pulp, all specimens after the hammer impact showed a small area of the surface concave and no cracks, are in line with the requirements of Japanese Industrial Standard JIS A1408: 2001. |
