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No / Precast concrete hollow core floor units (hcu) are widely used in all types of multistorey steel framed buildings where they bear onto the top flanges of universal beams. The steel beam is normally designed in bending, in isolation from the concrete slab, and no account is taken of the composite beam action available with the precast units. A program of combined experimental and numerical studies was undertaken that aimed at deciding on a suitable approach for the design of composite steel beams that utilize precast concrete hollow core slabs. The results show that the precast slabs may be used compositely with the steel beams in order to increase both flexural strength and stiffness at virtually no extra cost, except for the headed shear studs. For typical geometry and serial sizes, the composite beams were found to be twice as strong and three times as stiff as the equivalent isolated steel beam. The failure mode was ductile, and may have been controlled by the correct use of small quantities of tie steel and insitu infill concrete placed between the precast units.

No / The chapter discusses the behavior of composite steel beams with precast hollow core slabs in hogging moment regions. Full-scale composite beams to column semi-rigid connections with precast hollow core slabs are tested in the chapter. The chapter presents a steelwork connection consists of a flush end plate bolted to column flanges. The main variables studied are shear stud's spacing and degree of shear connection. Comprehensive instrumentations are used for all the tests, based on the experimental data, and equations to predict the rotation and the moment capacity for this type of composite connection are proposed in the chapter. A precast composite hollow core floor is a newly developed composite system for building that use precast hollow core slabs as the structural flooring. However, research on composite construction incorporating steel beams with precast hollow core slabs is still relatively new in comparison to the more traditional composite metal deck flooring.

No / Composite construction incorporating steel beams and precast hollowcore slabs is a recently developed composite floor system for building construction. As the construction industry demands for rapid construction with reduction in cost and environmental impacts, this form of composite construction, which does not require major onsite concreting, has become very popular among the designers and engineers in the UK. This form of composite construction is so far limited to simple beam-column connections. A semi-rigid composite joint is developed which can provide sufficient moment and rotation capacity required for plastic analysis in composite beams design. An analytical model for the semi-rigid composite connection is proposed and is verified with the experimental data and good agreement is obtained.

This article reviews the design and behaviour of composite beams with precast hollow core slabs in multi-storey buildings for gravity loading. A brief history of composite construction and introduction to precast¿composite construction is given, followed by an overview of recent research work on various factors affecting the design. This includes the push-off test procedure, the load¿slip characteristic of the headed shear studs and the design procedures for this type of construction. Finite element modelling of the headed stud shear connectors and the composite beams with precast hollow core slabs are presented. Finally, recommendations and future research work is also suggested.

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It is the major purpose of this thesis to examine, through a practical engineering problem, the different aspects affecting the development of the structural concept. For this purpose, a prestressed-precast concrete structural system for multi-story construction is developed. After the introductory sections, the development of the structural system is explained in the third section. The section includes an analysis of the system, as well as a description of the individual component of the structure and their interaction. The analysis provides a corroboration of the adequacy of the concepts of the system. Illustration aid in the explanation of the problems involved. / Master of Science

Full-depth precast deck panels are a promising alternative to the conventional cast-in-place concrete deck. They afford reduced construction time and fewer burdens on the motoring public. In order to provide designers guidance on the design of full-depth precast slab systems with their full composite strength, the horizontal shear resistance provided at the slab-to-beam interface must be quantified through further investigation. Currently, all design equations, both in the AASHTO Specifications and the ACI code, are based upon research for cast-in-place slabs. The introduction of a grouted interface between the slab and beam can result in different shear resistances than those predicted by current equations. A total of 29 push off tests were performed to quantify peak and post-peak shear stresses at the failure interface. The different series of tests investigated the surface treatment of the bottom of the slab, the type and amount of shear connector and a viable alternative pocket detail. Based on the research performed changes to the principles of the shear friction theory as presented in the AASHTO LRFD specifications are proposed. The proposal is to break the current equation into two equation that separate coulomb friction and cohesion. Along with these changes, values for the coefficient of friction and cohesion for the precast deck panel system are proposed. / Master of Science

Motivated by Robert Mast's original papers on lifting stability, this research study provides a method for predicting beam behavior during lifting, with application in the construction of bridges. A beam lifting cracking limit state is developed based on analytical equations for calculating the roll angle of the beam, the internal forces and moments, the weak-axis and strong-axis deflections, and the cross-sectional angle of twist. Finite element simulations are performed to investigate the behavior of concrete beams during lifting and to validate the proposed method. Additionally, a statistical characterization of beam imperfections is presented, based on recently conducted field measurements of beam lateral sweep and eccentricity of lift supports. Finally, numerical examples for two typical precast prestressed concrete beam cross-sections are included to demonstrate the proposed method. / Master of Science

The use of full-depth precast concrete bridge deck panels is becoming more and more attractive to transportation authorities throughout the country. In comparison to conventional cast-in-place decks, precast decks are of higher quality, allow for the bridge to be opened to traffic in less time and are easier to maintain, rehabilitate, and replace. This ultimately results in lower costs for transportation authorities and less disruption for the motoring public. Unfortunately, the use of precast deck panel systems is hindered by the lack of design standardization and information regarding the performance of such systems. This research focuses on a key element of the system, the mortar or grout, which is used to connect the precast panels to the bridge girders by filling the space in the horizontal shear pockets and the haunches. Several essential mortar characteristics were identified and investigated in order to create a specification that indicates required performance criteria for mortars. This specification can be used to determine whether particular mortars or grouts are suitable for use in a full-depth precast concrete bridge deck panel system. / Master of Science