Experimental Study On Mechanical Properties Of Laminated Bamboo Timber With Side Pressure

Like wood,bamboo is a kind of renewable green material.The utilization of bamboo is also accompanied by the development of human beings.China is one of the largest bamboo producing countries in the world.If we use bamboo as the main structural material in the field of civil engineering construction and develop a new type of bamboo structure system,it is very hopeful to become a new breakthrough point of green building.The side pressing bamboo is a kind of glued and pressed bamboo timber.The existing side pressing bamboo products are mainly for furniture manufacturing and high-end building decoration,but for building structural materials,the side pressing bamboo products also need to have physical and mechanical properties that meet the requirements of building structural materials.Obviously,it is necessary to study the raw material composition,production process and mechanical properties of the side pressing bamboo.In this paper,the basic physical and mechanical properties,the long-term compressive properties,the strength standard values and the design values of the side pressed bamboo are systematically studied and analyzed through experimental research and theoretical analysis.The main contents are as follows:(1)The moisture content and density of the laminated bamboo were measured,and the basic physical properties of the laminated bamboo were obtained.(2)Completed the lateral pressure of bamboo integrated timber mechanics performance test,the lateral pressure of bamboo integrated timber compressive strength,tensile strength,bending strength,shear strength,tensile modulus of elasticity and bending modulus of elasticity of average,statistical analysis of the various mechanical performance index of the standard deviation and coefficient of variation,and master the lateral pressure bamboo integrated timber under various stress failure pattern and failure mechanism.(3)The long-term compression performance test of the laminated bamboo timber was completed,and the relationship between the long-term deformation of the laminated bamboo timber and the stress level,ambient temperature and humidity was studied by loading three groups of prismatic specimens with different stress ratios for 200 days,the deformation law of laminated bamboo under long-term load was obtained.(4)Based on the structural reliability theory,the uncertain factors affecting the structural resistance of bamboo structures are analyzed,and the target reliability index and the partial coefficient of resistance are proposed.Based on the test data of the side-pressed laminated bamboo lumber,Pearson χ2 method is used to verify that the probability distribution of the measured values of the side-pressed laminated bamboo lumber obeys the normal distribution N(μ,σ2),based on the probability theory,the strength standard value and the strength design value of the laminated bamboo are given,which can provide reference for the design of the laminated bamboo structure.