Composite Concrete Structures

CHAPTER (1)

INTRODUCTION

1.1 General The composite concrete structures have been always a topic of major importance in the field of construction. The use of concrete in composite structures may be with steel sections in the form of steel-concrete composite sections, or with concrete cast at different times to form what is called concrete-concrete composite sections which are used in buildings and bridge constructions.

Economic considerations indicate the desirability of composite action between the precast and the cast in place elements. Composite behavior, with the slab serving as the flange of T-beam results in horizontal shearing stress at the construction joints.

The stresses at this region are very complicated and several trials to represent the behavior in this region have been made.

Precast concrete with cast in place slabs have this advantage. There is an urgent need for further investigations, laboratory tests, numerical analysis and theoretical studies to find an acceptable method for solving the problem of shear transfer along the interface between precast concrete and cast-in-place concrete to simplify dealing with such structures as the need for them is becoming urgent.

1.2 Advantages and disadvantages of composite concrete section In concrete-concrete composite structures the precast beam acts as a form for the cast in place slab. According to some economic considerations for the application of such structures some of the advantages and the problems of this type of construction are summarized are