We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard （CBPB） containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portla...We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard （CBPB） containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portland cement mixed with different levels of inorganic additives. We determined the setting time and compression strength of cement pastes containing different additives and particles, and studied the effects of these additives and particles on thickness swelling, internal bond strength and modulus of rupture of CBPB by using RSM （Response Surface Methodology）. The mathematical model equations （second-order response functions） were derived to optimize properties of CBPB by computer simulation programming. Predicted values were in agreement with experimental values （R2 values of 0.93, 0.96 and 0.96 for TS, IB and MOR, respectively）. RSM can be efficiently applied to model panel properties. The variables can affect the properties of panels. The cement composites with bending strength 〉 12.5 MPa and internal bond strength 〉 0.28 MPa can be made by using wheat straw as a reinforcing material. Straw particle usage up to 11.5% in the mixture satisfies the minimum requirements of International Standard, EN 312 （2003） for IB and MOR. The dose of 4.95% calcium chloride, by weight of cement, can improve mechanical properties of the panels at the minimum requirement of EN 312. By increasing straw content from 0 to 30%, TS was reduced by increasing straw particle usage up to 1.5% and with 5.54% calcium chloride in the mixture, TS satisfied the EN 312 standard.展开更多
We evaluated the potential use of amino silane coupling agent （SiNH） to improve physical and mechanical properties of UF-bonded wheat straw （Triticurn aestivum L.） poplar wood particleboard. We examined the effect...We evaluated the potential use of amino silane coupling agent （SiNH） to improve physical and mechanical properties of UF-bonded wheat straw （Triticurn aestivum L.） poplar wood particleboard. We examined the effects of varied content of silane coupling agent content and ratios of straw to poplar wood particles on particleboard prop- erties. The ratios of straw to poplar wood particles were 100：0, 85：15, 70：30 and 55：45. Silane coupling agent content was tested at three levels, 0, 5 and 10 %. The experimental panels were tested for their mechanical strength, including modulus of elasticity （MOE）, modulus of rupture （MOR）, intemal bonding （IB） and physical properties according to procedures specified in DIN 68763 （Chipboard for special purposes in building construction： concepts, requirements, testing, 1982-03, 1982）. All board properties were improved by the addition of silane cou- pling agent. The use of poplar wood particles had a positive effect on the mechanical properties of wheat straw parti- cleboard but had a negative effect on physical properties （thickness swelling and water absorption）.展开更多
An attempt has been made to assess the productivity as well as the carbon sequestration potential of this mixture. The grain as well as straw yields were significantly lower in poplar block plantations than in the op...An attempt has been made to assess the productivity as well as the carbon sequestration potential of this mixture. The grain as well as straw yields were significantly lower in poplar block plantations than in the open （14 to 64% and 13 to 66% grain and straw yield, respectively under one to six year plantation）. The annual productivity of poplars was recorded maximum after fourth year and later the annual wood increment decreased （42.4, 39.8 and 35.6 m^3/ha/yr after 4^th, 5^th and 6^th year, respectively）. The enrichment of soil through litter and roots enhanced the organic carbon in the surface layer of soil （0-15 cm） under poplar blocks as compared to open fields with wheat crop only. The carbon storage potential in agroforestry system was recorded very high in comparison to sole crop. The carbon storage in agroforestry system increased with the age of the plantation and the major contribution came from the timber, roots and litter （37.30 mg/ha after six years）. However, wheat crop yield decreased under poplar but this may be compensated by the poplar trees in terms of biomass, economic returns and the carbon sequestration potential.展开更多
We used silane coupling agents to improve the bonding ability between wheat straw particles and UF resin, and investigated surface properties （wettability and surface roughness） and hardness of parti-cleboard made f...We used silane coupling agents to improve the bonding ability between wheat straw particles and UF resin, and investigated surface properties （wettability and surface roughness） and hardness of parti-cleboard made from UF-bonded wheat straw （Triticum aestivum L.） combined with poplar wood as affected by silane coupling agent content and straw/poplar wood particle ratios. We manufactured one-layered particleboard panels at four different ratios of straw to poplar wood par-ticles （0%, 15%, 30% and 45% wheat straw） and silane coupling agent content at three levels of 0, 5% and 10%. Roughness measurements, average roughness （Ra）, mean peak-to-valley height （Rz）, and root mean square roughness （Rq） were measured on unsanded samples by using a fine stylus tracing technique. We obtained contact angle measurements by using a goniometer connected to a digital camera and computer sys-tem. Boards containing greater amounts of poplar particles had superior hardness compared to control samples and had lower wettability. Panels made with higher amounts of silane had lower Rq values.展开更多
基金supported by Department of Wood and Paper Science and Technology,University of Zabol
文摘We investigated the hydration behavior and some physical/mechanical properties of cement-bonded particleboard （CBPB） containing particles of wheat straw and poplar wood at various usage ratios and bonded with Portland cement mixed with different levels of inorganic additives. We determined the setting time and compression strength of cement pastes containing different additives and particles, and studied the effects of these additives and particles on thickness swelling, internal bond strength and modulus of rupture of CBPB by using RSM （Response Surface Methodology）. The mathematical model equations （second-order response functions） were derived to optimize properties of CBPB by computer simulation programming. Predicted values were in agreement with experimental values （R2 values of 0.93, 0.96 and 0.96 for TS, IB and MOR, respectively）. RSM can be efficiently applied to model panel properties. The variables can affect the properties of panels. The cement composites with bending strength 〉 12.5 MPa and internal bond strength 〉 0.28 MPa can be made by using wheat straw as a reinforcing material. Straw particle usage up to 11.5% in the mixture satisfies the minimum requirements of International Standard, EN 312 （2003） for IB and MOR. The dose of 4.95% calcium chloride, by weight of cement, can improve mechanical properties of the panels at the minimum requirement of EN 312. By increasing straw content from 0 to 30%, TS was reduced by increasing straw particle usage up to 1.5% and with 5.54% calcium chloride in the mixture, TS satisfied the EN 312 standard.
文摘We evaluated the potential use of amino silane coupling agent （SiNH） to improve physical and mechanical properties of UF-bonded wheat straw （Triticurn aestivum L.） poplar wood particleboard. We examined the effects of varied content of silane coupling agent content and ratios of straw to poplar wood particles on particleboard prop- erties. The ratios of straw to poplar wood particles were 100：0, 85：15, 70：30 and 55：45. Silane coupling agent content was tested at three levels, 0, 5 and 10 %. The experimental panels were tested for their mechanical strength, including modulus of elasticity （MOE）, modulus of rupture （MOR）, intemal bonding （IB） and physical properties according to procedures specified in DIN 68763 （Chipboard for special purposes in building construction： concepts, requirements, testing, 1982-03, 1982）. All board properties were improved by the addition of silane cou- pling agent. The use of poplar wood particles had a positive effect on the mechanical properties of wheat straw parti- cleboard but had a negative effect on physical properties （thickness swelling and water absorption）.
文摘An attempt has been made to assess the productivity as well as the carbon sequestration potential of this mixture. The grain as well as straw yields were significantly lower in poplar block plantations than in the open （14 to 64% and 13 to 66% grain and straw yield, respectively under one to six year plantation）. The annual productivity of poplars was recorded maximum after fourth year and later the annual wood increment decreased （42.4, 39.8 and 35.6 m^3/ha/yr after 4^th, 5^th and 6^th year, respectively）. The enrichment of soil through litter and roots enhanced the organic carbon in the surface layer of soil （0-15 cm） under poplar blocks as compared to open fields with wheat crop only. The carbon storage potential in agroforestry system was recorded very high in comparison to sole crop. The carbon storage in agroforestry system increased with the age of the plantation and the major contribution came from the timber, roots and litter （37.30 mg/ha after six years）. However, wheat crop yield decreased under poplar but this may be compensated by the poplar trees in terms of biomass, economic returns and the carbon sequestration potential.
文摘We used silane coupling agents to improve the bonding ability between wheat straw particles and UF resin, and investigated surface properties （wettability and surface roughness） and hardness of parti-cleboard made from UF-bonded wheat straw （Triticum aestivum L.） combined with poplar wood as affected by silane coupling agent content and straw/poplar wood particle ratios. We manufactured one-layered particleboard panels at four different ratios of straw to poplar wood par-ticles （0%, 15%, 30% and 45% wheat straw） and silane coupling agent content at three levels of 0, 5% and 10%. Roughness measurements, average roughness （Ra）, mean peak-to-valley height （Rz）, and root mean square roughness （Rq） were measured on unsanded samples by using a fine stylus tracing technique. We obtained contact angle measurements by using a goniometer connected to a digital camera and computer sys-tem. Boards containing greater amounts of poplar particles had superior hardness compared to control samples and had lower wettability. Panels made with higher amounts of silane had lower Rq values.
