Design,Manufacture And Evaluation Of Graded Glued Bamboo Lamination For Marine Use

With the development of bamboo industry in China,more and more bamboo product are applying in the market,such as bamboo plywood from thin bamboo strips,bamboo oriented strand board,bamboo scrimber and glued laminated bamboo and so on.Glued laminated bamboo of which the basic unit is bamboo strips is mainly used in furniture and flooring area.The research object of this article is moso bamboo(Phyllostachys edulis)strips which is regarded as dimension bamboo strips by size measurement and graded by density and modulus of elasticity(MOE).Graded glued bamboo lamination is manufactured using the corresponding graded dimension bamboo strips with the method of continuous ladder breaking assembly and hot pressing process,and the physical and mechanical properties of dimension bamboo strips of different density grade and corresponding graded bamboo lamination is evaluated.Glubam(glued laminated bamboo)is manufactured with bamboo lamination,and the backbone of a boat is designed and manufactured for demonstration.The main research results of this study are as follows:(1)Custom bamboo strips,of which the size is stabilized and meets the definition of the dimension bamboo strips.Its air-dry density distributes in 0.50 to 0.95 g/cm~3,and the main density range for use is 0.50 to 0.85 g/cm~3.The grading method based on air-dry density is established with 0.05 g/cm~3 interval length dividing the density.The main MOE ranges from 6 to 13 GPa,and the method based on MOE is established with 1 GPa interval length dividing the MOE.(2)The result of mechanical properties for 7 grade of D50 to D80 dimension bamboo strips shows that MOE and the mechanical strength values are positively correlated with density.The tangential and radial MOE can be derived due to their good linear dependence(R~2 is between 0.96 to 0.99).Among the mechanical properties of the same grade dimension bamboo strips,the bending strength is greater than the tensile strength parallel to grain,the next is compression strength parallel to grain which is greater than the compression strength perpendicular to grain,while the tensile shear strength is minimal.(3)The continuous and non-continuous bamboo lamination of corresponding density grade is made from the same density grade dimension bamboo strips.The result shows that there is no cross area of density between different grade which ranges from 0.47 to 0.80 g/cm~3,and the MOE ranges from 6 to 14 GPa.(4)The result of mechanical properties for glued bamboo lamination of all grades shows that MOE and the mechanical strength values are positively correlated with density,but with the increase of density,the three point bending impact toughness first increases and then decreases,while puncture impact toughness is negatively correlated with density.The result shows that the performance variability of the same density grade bamboo lamination is small.The linear correlation of the density with MOE and MOE with MOR of continuous bamboo lamination falls compared with the non-continuous bamboo lamination.(5)Internal water of bamboo transfers mainly along the length wise direction,and the end-sealing method can make the rate of water transmission decline effectively.There is fifferent dry shrinkage rate and bulking factor in different density grade dimension bamboo strips,and the water bath temperature has significant influence to the bulking factor.The resorcinol resin adhesives is more suitable for bonding bamboo lamination campared with the epoxy resin adhesives.(6)A small sample of ship structure is designed and made using bamboo lamination and glubam as the main frame components such as the main keel,plate floor and bamboo stringers.It provides the bases for bamboo structure material apllication in the shipbuilding industry.