STRENGTHENING OF R.C. BEAMS USING EXTERNALLY BONDED PLATES AND ANCHORS

Premature plate end debonding failure is the main weakness of plate bonded strengthened beams which can be minimized by end anchors. The main objectives of this research were to study the behaviour of steel plate and CFRP laminate strengthened r.c. beams, the effects of U and L shape end anchors to prevent plate end debonding and the effects of L shape intermediate anchors to eliminate premature shear. Nine rectangular beams were tested. Design methods were proposed to obtain the dimensions of steel plate and CFRP laminate. U and L shape end anchors were used on steel plate and CFRP laminate strengthened beams. The length of end anchors was obtained from the proposed design theory. L shaped intermediate anchors were provided in the shear span of L shaped end anchored strengthened beams. Results exhibited that both U and L shaped end anchored strengthened beams showed ductile failure modes without premature end peeling with higher failure loads, less deflection and less cracks compared to the un-anchored beams. Intermediate anchors prevented premature shear failure.The proposed design methods were experimentally satisfied.