Feasibility Study On Double Ribbed I-Shaped Bamboo Laminated Hollow Slab As A Steel Structure Floor Slab

In steel frame civil buildings,floor slabs play an important role in bearing and transmitting loads.The current forms of steel structure floor slabs,such as concrete composite slabs,profiled steel plate concrete composite slabs,and reinforced truss concrete composite slabs,all require a large amount of cast-in-place concrete during construction,resulting in high labor consumption and long construction cycles,making it difficult to meet high assembly requirements.How to design a new type of floor slab that is lightweight,high-strength,easy to construct,and easy to assemble is of significant significance for the enrichment and development of steel structure floor forms.In view of this,this article designs a "double ribbed I-shaped" bamboo laminated hollow slab and conducts the following research:(1)Conduct wood properties tests on carbonized bamboo laminated timber,referring to the corresponding specifications of "Test Methods for Physical and Mechanical Properties of Building Bamboo Timber"(JTG199-2007)and "ASTMD198-02",to determine the natural density,moisture content,compressive strength,tensile strength,flexural strength,and elastic modulus of bamboo laminated timber.Analyze typical failure modes during compression,tensile strength,and bending processes along the grain,Obtain corresponding mechanical parameters to guide structural design.(2)Design a total of 11 floor units consisting of three sets of adhesive nail combination connecting plates with different cross-sectional parameters,including flange thickness,rib width,and rib height,and a set of pure adhesive connecting plates.By conducting a four point bending experiment,the failure phenomena and modes during the bending process were studied.Analyze the load displacement curve,section strain curve,and load strain curve during the bending process of the plate,and explore the effects of three different section size parameters and different connection forms on the bending bearing capacity and stiffness of the plate.(3)The ultimate bending bearing capacity of the board was calculated through classical elastic theory,and the results were greater than the experimental measured values.Traditional wood structure design methods are not suitable for bamboo laminated timber.On this basis,the plastic development of the plate is considered through nonlinear theory,and three different models,namely the ideal elastic-plastic model,the double line model,and the quadratic curve model,are proposed.The bending bearing capacity and deflection formulas are derived,and compared with the measured results.Revise the elastic theory formula and provide simplified calculation formulas for bending bearing capacity and deflection to guide engineering design.The bending bearing capacity and deflection of YYH-2 slab were calculated with a 6-meter span to meet the requirements of the specifications,and the cross-sectional dimensions of the slab were optimized based on the five commonly used spans of steel structures in civil architecture.(4)The ABAQUS software was used to simulate the four point bending of the adhesive nail composite connection plate and the pure adhesive connection plate,and the failure process and mode were in good agreement with the experimental results.Based on the size of LBG-2 specimens,parameter analysis is conducted to further investigate the effects of screw depth,screw spacing,and aspect ratio on the bending performance and stability of the plate,and provide reference dimensions for practical applications.(5)The bamboo composite hollow core slab and the conventional pressed steel plate concrete composite slab are built in an 8-story steel frame structural model,and modal analysis,response spectrum analysis and time course analysis are performed for the two different structural forms.The differences in acceleration response,displacement response and base reaction force of the top floor under X-directional multiple encounter earthquake and rare encounter earthquake are compared.The overall seismic performance of the bamboo composite hollow-core slab is better than that of the compressional steel and concrete composite slab under rare earthquakes.