Experimental Investigations And Design Method On Engineered Bamboo-ALC Composite Panel

Bamboo has been a traditional construction material in many regions for centuries from the ancient times.The rapid growth and maturation rate of bamboo,its good properties and global accessibility make it a promising building material resource.In recent years,China has implemented the goals of "Peak Carbon Emission" and "Carbon Neutrality".As a negative carbon material,bamboo can effectively reduce the carbon emissions of the construction industry and help achieve the national "Double Carbon" strategic goal.However,due to limited standardization and design criteria,bamboo has often been relegated to non-engineered and marginally-engineered material.Composite structural components made of engineered bamboo are also becoming more and more abundant.Based on the concept of ecology and lightness,the current study introduces a novel bamboo-autoclaved lightweight sand aerated concrete(ALC)composite panel’s static performance and design methods under axial and bending loads.The proposed novel composite panel composes of the engineered bamboo face and ALC core with bolt shear connection or bolt and adhesive connections based on the sandwich panel concept to enhance the composite performance.Static test of composite panels under axial load and under bending were carried out to investigate the failure modes,stress-strain,and load versus displacement relationship.The engineered bamboo was tested to obtain the modulus of elasticity,strength and rapture for engineered bamboo.Can be noted that increasing the face thickness for under axial load from 9 mm to 13.5mm,the value of ultimate bearing capacity,initial stiffness and ductility index of the bamboo-ALC composite panel was increased by 51%,50% and 3%,respectively.Similarly,changing shear connection type from bolt to bolt/adhesive,the ultimate bearing capacity increases by 16% due to the adhesive solidification of bamboo to concrete.In contrast,the initial stiffness and ductility of the bamboo-concrete sandwich panel decreases by 11% and9%,respectively.The observed failure mode of the bamboo-ALC composite panel was buckling,fracture and overall buckling in some specimens,followed by concrete cracks.Concerning under bending load,the observed failure mode of the bamboo-ALC composite panel was bending failure and a fracture on bamboo,followed by ALC cracks near the middle span.For the steel-ALC composite panel,the failure mode was shear failure and steel buckling,followed by ALC cracks.The comparison of bamboo-ALC composite panel to steel-ALC composite panel approved that the performance of bamboo-ALC composite panel is better than steel-ALC in terms of its high strength-to-weight ratio.The ultimate bending capacity of the bamboo-ALC composite panel increased by 42.1 % with increases of the face thickness from 9 mm to 13.5 mm,increased by 37.5 % with changes of shear connection from bolt to bolt with adhesive and increased by 28.8 % with increases of core thickness from 100 mm to 150 mm.Using ABAQUS software,the finite element models of the bamboo-ALC composite panel were established,considering the geometric and material non-linearity.At the same time,the applicable bamboo and ALC constitutive model was selected.The failure modes,bearing capacity and stress process were compared with the experimental results to verify the reliability of the established finite element models.Based on the numerical analysis results,the deformation,failure mode,stress process distribution and ultimate loads of bamboo-ALC composite panel were in good relation with test results for both under axial load and bending load.The equations for the ultimate bearing capacity of the bamboo-ALC composite panel under the axial load and bending load are established and verified by experimental results.To quantify the perceived benefits and outstanding recorded structural performance of the bamboo-ALC composite panel under bending load,a brief comparison between the bamboo-ALC composite panel test results and the other two different types of panels previously reported was discussed which indicates that the bamboo-ALC composite panel has the advantages of lighter weight and higher strength.