Provision of utility and service ducts are important part of modern building construction. To facilitate fast and
uninterrupted progress, the layout of these ducts are planned in advance. Their positions are decided considering the
head room provisions in buildings, aesthetic look, etc., without jeopardizing the strength, stability and serviceability of the
structures. To fulfill these aspects, often ducts have to pass through main load bearing elements like beams. The present
work is to explore the behavior of rectangular RCC beams with circular opening under torsion load. The torsional
capacity of beams with opening are extracted experimentally. The study is extended by retrofitting the beams with four
layers of bidirectional woven GFRP fabric applied by following orientation 90/90/90/90.The restoring torsion capacity,
crack patterns are observed and the strength has been increased by retrofitting.