EFFECTS OF OPENINGS IN RC BEAMS SUBJECTED TO STATIC AND CYCLIC LOADS

The structural engineers are often faced with the problems of providing convenient passage for environmental services in concrete beams used in parking garage, industrial and residential buildings, and sometimes bridges. The main function to penetrate RC members is to facilitate the passage of utility pipes and service ducts which results not only in a more systematic layout of pipes and ducts but it also translate into substantial economic savings in the construction of a multi-storey building. For example, for conveying the services and other facilities such as water supply, electricity, air-conditioning and sewerage discharge. The size, location and configuration of structural penetration are derived from the type of services, magnitude and speed of facility to be provided. Penetration means the loss of concrete area, which results in the reduction of resistance in the term of strength and axial stiffness. It may also affect the flexural or shear stiffness and deflection resistance of the beam.
In order to understand the behaviour of openings at controversial location and their mitigation using appropriate techniques; this research was carried out on RC beams with openings which were subjected to static and cyclic loading. This research also studies the prospect of strengthening the beams by using external bonded CFRP sheets and traditional method (additional reinforcement bars along the edges). The openings are circular, rectangular, square and elliptical shaped. Twenty identical RC beams with and without opening were cast and subjected to static and cyclic load In this research is found that beams with square and circular opening when subjected to static load gain its strength and reduces the deflection when pasted with CFRP sheets. Beam with elliptical and rectangular opening also increase its strength when added with additional reinforcement bars along the edges. As for cyclic load, beams with opening could stand more cyclic load rather than solid beam. Beam with opening is less heavier than solid beam and has opening to allow the energy to dissipate when cyclic is being applied on the beam.