Structural Behavior And Design Method Of Concrete Composite Slab With Precast Prestressed Concrete Ribbed Panel

It has been over for 60 years about the research and application of composite floor strcucture in America,Japan,Australia and other countries,but there still exist three problems.One is the domestic theoretical research and practical application obviously lag behind developed countries,and foreign enterprises have a great amout of proprietary intellectual properties which against domestic application.The second is the application of traditional prefabricated floors is restrained due to the poor properties of integrity,earthquake resistance and crack resistance;Among the numerous disadvantages over traditional composite floors with precast solid panel,are the great loss in transportation and construction,the uncontrolled quality,the support system during the installation process as well as the complexity of its construction.Cast-in-place floors have many disadvantages such as hard to install and remove formwork,the large amount of formwork using,relatively slow construction speed,the serious environmental pollution and noise pullution,as well as easy to produce temperature and shrinkage crack.In a word,the traditional building way exists many issues such as the waste of steel and wood,the environment pollution,high weight,cost-noneffective and slow construction speed.The third is the current standards at home and abroad relevant two-way slab floor static design method and fatigue design theory cannot be directly applied in this new style composite slab,which named composite slab with precast prestressed concrete ribbed panel,so more research work needs to be done.In view of the above two big problems,this dissertation will be divided into two parts:One is to resolve the static calculation and design problem based on the orthotropic rigidity.Based on the secondary load of the new style composite slab,with the orthotropic rigidity as the research object,the static calculation and design problem will be solved by FEM,stepped rigidity beam slab theory,orthotropic plate theory,yield line theory and experimental study,which might be useful for the further investigation.The research of the new style composite slab system would be great significance to enhance the new technology for building and the new process,and to promote the progress of science and technology in construction industry.Contents include:theoretical study on two-way effects of the new style composite slab;rigidity orthotropic characterization study;practical elastic and plastic design method based on rigidity orthotropic characterization.The other is to put forward the bending fatigue calculation and design theory.Reasonable detailing and designing of the contact surface play an important role in improving fatigue performance of the new style composite slab.Aiming at the problem of fatigue property of the new style composite slab with different detailing and designing of contact surfaces,static and fatigue tests are to be carried out on four groups of specimens which involve composite slab with precast solid panel,composite slab with precast rectangular holes-rib panel,composite slab with precast T-shaped holes-rib panel and cast-in-situ concrete slab.Cracking loads,ultimate loads,cracking distributions and failure patterns are to be investigated by static tests.The factors influencing the fatigue failure pattern and fatigue damage,such as shape of rib,preformed hole in the rib,transversal steel bar in the preformed hole,fatigue load parameter and fatigue cycle number,are researched by fatigue tests.Based on the theoretical analysis and experimental study,fatigue performance theory of the new style composite slab is to be presented,design method,design formula,design suggestion and detailing are to be proposed,which can offer the reliable basis for design and national standard or industry standard.