Study Of Ortho-hexagonal Core-moulded Hollow Floor Based On Multi-scale Analogue Slab Method

The composition of the cast-in-place concrete hollow-core floor cover is,from top to bottom,the top slab,the hollow sandwich and the bottom slab,with the core form of the hollow sandwich being wrapped by concrete ribs.The core form is placed in the reinforcement in a cyclically distributed manner during the reinforcement tying process,before being cast on-site to form the hollow core floor cover.By replacing the concrete in the same position with a hollow core form,the hollow floor cover optimises the structural stress distribution and reduces the self-weight of the structure.In this paper,a multi-scale analogue slab method(MASM)is proposed for the structural analysis of hollow roofs,and the equivalent elastic constants are obtained by multi-scale calculations of the hollow roof cell structure with the aid of finite element software for three different boundary conditions.The study also investigates the force-deformation characteristics of the hollow-cell structure with a hexagonal core under three different boundaries.The main research contents and conclusions of this paper are.(1)The general calculation procedure of the mathematical homogenisation theory(MHT)is derived,and a single-cell model of the ortho-hexagonal core-moulded hollow-core building cover is established;the equivalent modulus of elasticity of the single-cell is calculated using the MHT,and the calculation results are compared with those of the box-shaped hollow-core building cover single-cell.The results show that the ortho-hexagonal core-moulded hollow-core building cover is more resistant to deformation.(2)Based on the multi-scale slab fitting method and the direct modelling method,the internal forces and deformation patterns of hexagonal core hollow caps with different hollow ratios and boundary conditions under uniform load are investigated,and the reliability of the multi-scale slab fitting method is confirmed;the calculation results of stresses,deflections and bending moments of hexagonal core hollow caps and box hollow caps are also compared.The results show that the mechanical performance of the hexagonal core hollow cover is better.(3)The stresses and deflections of the hollow core and solid core covers are further analysed by considering both the self-weight and non-self-weight cases of the covers.The results show that the advantage of the hollow core building cover is that the deflection of the building cover only increases by 4.03% to 13.43% under the premise of reducing the self-weight of the building cover by 25% to 50%,saving the use of high carbon emission materials,energy consumption,etc.,while having good social and economic benefits.