Experimental investigation of strengthening slab-column connections with CFRP fan

Abstract

This paper investigates experimentally the punching shear behavior of flat slabs-column connections strengthened with CFRP (Carbon fiber reinforced polymer) string having a fan shape as a new strengthening technique. Six square slabs with middle column heads were casted monolithically at the center of the slabs. All the specimens had the same dimensions and the same reinforcement detailing. Four slabs were strengthened with CFRP fan, one strengthened with steel bolts while the reference specimen was tested without strengthening.The results showed that the proposed strengthening technique improved the punching shear capacity and enhanced the ductility of the flat slabs column connections compared with un-strengthened connections. Punching shear failure load achieved by experimental testing showed a reasonable agreement with the calculated punching failure loads based on formulas adopted by different codes: ECP (Egyptian code of practice), ACI-318 (American concrete institute) and JSCE (Japan society of civil engineers). Keywords: Punching shear strengthening, Flat slabs, RC, CFRP fan