NUMERICAL STUDY OF R.C FLAT SLABS WITH OPENINGS STRENGTHENED BY USING NSM TECHNIQUES AND SUBJECTED TO FLEXURE

This study presents a model suitable simulate one way R.C flat slab with overhang have rectangular opening strengthened by using NSM techniques by using finite element modeling. ANSYS computer program version 12 is utilized in the analysis and four models slabs were performed each slab 2000mm span and 1000mm width. The overall thickness of slab is 120mm, clear span (distance between supports) of 1200 mm and the cantilever length is 700mm. Upper and lower steel reinforcement mesh Ø10@160mm (7Ø10/m). The opening dimensions were (400*200 mm) and the opening positions were considered near the maximum negative (hogging) moment region at distance 100mm from the intermediate support. In this research the effect of opening presence on R.C flat slabs was discussed and also the effects of using different strengthening NSM techniques around opening were studied. Based on results, the ultimate load of slab decreased due to presence of opening and then increase because of strengthening around opening compare to the slab without opening.