Experimental Study Of Long Span Cast-in-Situ Concrete Cellular Voided Two-Way Plates Supported By Edge Members

The cellular voided cast-in-situ concrete plate is a new kind of hollow plates in which many smaller boxes are embedded orderly as inter forms. Up to now,the research of the cellular voided floor plates are rather limited. This paper studies of the long-span cast-in-situ concrete cellular voided two-way plate supported by edge members including its elastic calculation method,finite element analysis,cellular voided plate test subjected to vertical uniformly distributed load,calculation method of torque of edge beams,three application examples of engineering projects and the suggestions of design and construction details,the main contents are as follows.1.The cellular voided cast-in-situ concrete plates are a kind of plates strengthened by dense two-way ribs. By means of the theoretical analysis and test results,this paper points out when l₁/(s₁-b₁)≥9,l₂/(s₂-b₂)≥9,and t/h≥1/4,the influence caused by shear lag can be ignored,the deformations of ribs and slabs between ribs can be considered as the same,then the plates can be analyzed by elastic plate theory,and the plates are called cellular voided plates. Here,l₁ and l₂ are the calculation span lengths of the plate in the short and long directions respectively,b₁ and b₂ are the widths of ribs in the two directions, and are the center to center distances of ribs in the two directions, is the thickness of slab between ribs, is the total thickness of the cellular voided plate including the ribs. Meanwhile this paper points out that cellular voided plates are the plates with ribs and the ribbed or waffle plates are the cross girder system with slabs as its wingspan. This paper also points out that if the cellular voided plates are analyzed as ribbed or waffle plates,thoroughly wrong results will be gained.2.Based on the tiny deflection theory of the elastic thin plates,the differential equations of the cellular voided plates are given. According to the peculiarity of the cellular voided plates,calculation formulae of the flexural and torsional stiffness are presented. The analytical solution of deflection and bending moment for cellular voided plates simply supported by four edges are given. The numerical solution of deflection and flexural moment for cellular voided plates fixed supported by four edges are also given. For engineering application,computer programs are compiled,coefficients of the deflection and bending moment are given for the plates with simply or fixed supported edges.3.By means of the solid element method,elastic finite element analysis and comparisons on a number of ensamples using ANSYS are carried out. The results show that the method presented in this paper can exactly calculate the deflection and bending moment of the cellular voided plates supported by four edges.4.A 4m×4m cellular voided concrete plate specimen is tested. The test results show that the deformations,cracks,collapse mechanism and etc of the cellular voided plate subjected to vertical uniformly distributed load are quite similar to those of the solid plates. The test results also show that the cellular voided plates hold many...