| In order to respond the development needs of the Twelfth Five-Year Guideline and Housing Industrialization, the proportion of fabricated structure is increasing in building engineering. With the further study of fabricated structure, fabricated structure has been widely applied. Fabricated structure has the characteristic of high industrialized degree, quality assurance and convenient construction ect and are mainly with precast unidirectional plate in modulus factory production due to the restriction of transportation. Not satisfying with the requirement of large span structure, how to turn unidirectional plate into two-way slab has been the most important problems that should be solved, which will increase application in fabricated structure and speed up process of housing industrialization.Two-way composite slabs can not be fabricated in factory due to the restriction of transportation and need to be divided into few unidirectional plates. Few unidirectional plates are composed into one two-way composite slab by the connection of the joint.Because of the weak mechanical behavior in the joint that can not satisfy the requirement of the bearing capacity, a structure form of the joint is recommended in this paper. Based on the arrangement on the test data of unidirectional plate and two-way slab and numerical simulation of test specimens, deformation performance of composite slabs under loads are studied. The design points of two-way composite slabs with joint are given at the end of the paper. The main work and research contents are as follows:(1)Based on the arrangement and analysis on the test data of unidirectional plate and two-way slab, the variation of the mid-span deflection in unidirectional plate and two-way slab under load is obtained.(2)Based on the derivation of calculation formula in Chinese code of short-term stiffness, the limitation of calculation formula in stiffness is analyzed. Based on the theory of substructure, the stiffness of the lattice steel in composite slab is proposed using equivalent stiffness and stiffness contribution of lattice steel in composite slab is analyzed. The calculation formula of stiffness in composite slab with lattice steel is also obtained. On the foundation of stiffness calculation formula in unidirectional plate shall be multiplied by a enhancement coefficient, for the stiffness of two-way composite slab normally stronger than unidirectional plate. After that the reductionfactor is needed to obtain equivalent stiffness calculation formula, for the secondary load and deformation existed in precast composite slab.(3)The specimens of the unidirectional plate and two-way slab is numerically simulated. The simulation results and the test results are compared, which proves the reliability of the simulation and provides references to related research.(4)Introducing processing method of unidirectional plate in joint, analyzing mechanical behavior in joint. Referring new enhanced connection form in joint,summarizing design points in two-way composite slab, which makes identification capacity is available between two-way composite slab with joint and cast-in-place two-way composite slab. |
