Structural performance of continuous RC slabs strengthened in negative moment regions with a mineral‐based composite

Abstract

An experimental programme was proposed and carried out to assess the effectiveness of the mineral-based composite (MBC) technique for the flexural strengthening of negative moment regions in continuous reinforced concrete slabs. In addition to the testing of the two reference specimens, the experimental programme included the testing of nine continuous RC slab specimens with different strengthening techniques, namely, using ordinary steel bars and MBC material. This experimental programme was conducted to study the failure modes, the load-deflection behaviour and the failure loads. Furthermore, we present and describe a comparative study between the two strengthening techniques, namely, steel reinforcing bars with MBC or steel bars with epoxy mortar. Based on the experimental results presented, both strengthening techniques for continuous slabs are evidently efficient. In this study the measured results for the average crack spacing were compared with the limits stipulated in CEB-FIP code 1990 and the failure load calculations were extended with an analytical approach based on the ultimate theory for the failure load calculation. In conclusion, the results obtained from the analytical model are in agreement with the experimental results.

Using high-performance cementitious mortar and external prestressing for retrofitting of corroded reinforced concrete beams

“…In this study, ductility was described through two indices. The first ductility index is the energy absorbed by the beam, which was indicated as the area under the load deflection curve (toughness) and estimated at 80%–90% of the peak load at the descending curve as studied by Atta et al (2016), as listed in Table 4. The second index is the ratio between the deformation at the ultimate load to that at the yield load as per El-Maaddawy (2014) as shown also in Table 4.…”