Research On Mechanical Properties Of Unsupported Composite Slab

Concrete laminates are a frequently used structural form in modern industrial building floor systems.It consists of prefabricated concrete slabs with a post-cast concrete upper part.However,the prefabricated floor slab thickness of ordinary concrete laminated slabs is generally only 50-70 mm,which is easily damaged by construction loads.Even if protective measures such as special brackets are taken during the construction process,it is still difficult to completely avoid the occurrence of damage.This can also lead to problems such as cracks or deformation of the floor surface,which is detrimental to the aesthetics and service life of the building.In addition,the prefabricated floor is difficult to bear various structural loads during the construction process,and a large number of vertical installation supports are required to support the laminated slab.These supports not only need to be leased,but also need manpower to carry and install,thereby increasing the cost of construction.At the same time,due to the need to install these supports,the construction period will be prolonged,affecting the progress of the construction period,which may lead to delays in the entire project.Facing the above shortcomings,this thesis studies the bending performance and working mechanism of the unsupported laminated slab by comprehensively using the means of experiment,finite element simulation and theoretical calculation.The auxiliary beam that can be used for turnover is placed under the concrete floor,and through the bolt Connected with the bottom plate,the theoretical calculation method of the deflection of the support-free laminated slab is established and verified,which provides a reference for the application of the support-free laminated slab.The main work of the thesis is as follows:(1)This study aims to calculate the stiffness and deflection of various types of truss laminated slabs,including unreinforced,ordinary concrete reinforced,prestressed,and unsupported truss laminated slabs.The analysis will also cover different forms of unsupported truss laminated slabs.The study will utilize the existing laminated slab atlas in combination with other methods.Results show that the stiffness of plywood is increased compared to the effect of ordinary truss laminated plate.(2)Two unsupported truss laminated slabs with varying spans underwent static testing to analyze their bearing capacity,crack resistance,integrity,and damage.(3)Finite element analysis software was utilized to conduct a model analysis of unsupported slabs with varying spans,slab widths,auxiliary beam specifications,and auxiliary beam lengths.This study aimed to investigate the structural characteristics and optimal design of unsupported slabs.The mechanical properties of different forms of unsupported laminated panels were analyzed by comparing the simulated data,test data,and theoretical data.