Experimental Study Of An Innovative Assembled Integral Two-Way Multi-Ribbed Composite Floor

With the development of construction industrialization in China,prefabricated buildings have been continuously ungraded towards green and intelligent construction.Based on the background,an innovative assembled integral two-way multi-ribbed composite floor is proposed,studying the stress mechanism and verifying the reliability.The system is composed of precast ribbed panel bay,mold box and cast-in-situ concrete topping.Inheriting from composite and two-way ribbed floor system,it not only has the advantages of two floor systems,but also effectively solves many problems in traditional engineering application.In this dissertation,the multi-scale experimental research and finite element simulation analysis on the mechanical performance of joints,overall mechanical performance,natural vibration characteristics and comfort of the innovative floor system were carried out,and calulation methods and design suggestions were put forward,which lays foundation for popularization and application.The main contents and conclusions are as follows:1.Study on mechanical behavior of joint of the assembled integral two-way multiribbed composite floorBased on the structural form of the innovative assembled monolithic composite floor system,four groups of cast-in-situ slabs and eight groups of composite slabs with different joint types were designed.To study the bending and shearing proprieties of the specimens,the threepoint static loading test was carried out.According to the experimental results,the ratios of experimental result to the theoretical calculation were all greater than 1.9,that showed the theoretical calculation and joint design of the new floor were reasonable and the connection mode of mechanical extrusion sleeve was reliable.2.Study on the overall mechanical performance of the assembled integral two-way multi-ribbed composite floorTo study the overall mechanical performance of the innovative assembled monolithic composite floor system with two-way ribs,a specimen with size of 9.2m×9.2m was designed.The test results showed that the innovative assembled monolithic composite floor system met the requirements of normal use load and ultimate load of bearing capacity.3.Finite element simulation on mechanical behavior of the assembled integral twoway multi-ribbed composite floorSolid models of the innovative assembled monolithic composite floor system with twoway ribs was built in ABAQUS.The experimental results showed that the error between finite element simulation and experimental results was within 15%,and the finite element method can be used as an effective means to study the mechanical performances of both the wholescale floor system and its joints.4.Force transfer mechanism and design theory of the assembled integral two-way multi-ribbed composite floorTo verify the applicability of the analogue beam method and the analogue slab method,parametric analysis and comparison of bending capacity of one-way and two-way slab were carried out by finite element method.A simplified design method was proposed.5.Testing of characterization and comfort of the assembled integral two-way multiribbed composite floorThe assembled integral two-way multi-ribbed composite floor was tested by dynamic measurement method under single,multiple person walking and running loads.It can be seen from the measured acceleration time course curves that there were no floor resonances under the single person,multiple persons’ walking or running condition during actual application.6.Theoretical calculation of the assembled integral two-way multi-ribbed composite floorBased on analytical calculation of the two-way slab and experimental results of key components,an elastic-plastic bilinear model was proposed to coincide the load-deflection relation of composite floor system,with the calculation method of key points derived.Compared with the experimental results,this method was found that the error of the bilinear model is less than 15%,which set a theoretical foundation for the innovative assembled monolithic composite floor system with two-way ribs to be used for other extreme working conditions.