Preparation Of Wood-based Magnesia Composite Material And Its Application In Prefabricated Construction

Wood based composite magnesia material,a new type of composite material,is made from discarded plywood,straw and magnesite cement.Its structure can be "sandwich" and "hollow".As one of the main timber for assembled building,it has important signficance in environmental protection and resource cyclic utilization.Preparation process,performance testing and analysis of wood-based magnesia composite material was study in this paper.The effect of surface magnesite cement thickness on panel's performance was investigated.A case,in the end,was given to illustrate the appication in prefabricated construction.The results were as follows:(1)The panel had heavy thickness deviation and the area density was big.The internal bonding strength was 0.23 MPa,which shows the poor performance of core plywood.Mechanical strength was poor due to the core layer plywood performance and assembling ways.MOR and MOE were 21.1 MPa.and 6620 MPa respectively,indicating that Surface layer magnesite cement has high mechanical strength.Also,its impact resistance,scratch resistant and anti halogenation had high performance,but water resistance was not.The magnesite adhesive had high bonding strength,which can be 1.01 MPa,but thermostability and boiling water resistance were poor.(2)MOR and MOE of Panel was improved,TS value decreased after the structure optimization.Maximum bonding strength,0.53MPa,was found when magnesite cement layer thickness is 3mm.We can see from the comprehensive results that the optimum thickness of panel is 3mm.(3)Wood based composite magnesia material's density was 35kg/m2,the bending load was 8.1 times of sheet,the fire resistance limit was 188min,?cr was 1.39 and average load of fracture specimen can be 18.74 KN/m2,when its structure was hollowcore board.We can see from the texting results that plate has high performance,such as light weight,high strength,water resistance,fire resistance and good structural performance(4)The Prefabricated construction is a green and environmental protection building,has good seismic performance,water resistance,flame retardant property,aging resistance,frost resistance and speedy construction.