Enhancement in the Load-Carrying Capacity of Reinforced Concrete Corbels Strengthened with CFRP Strips under Monotonic or Repeated Loads

Abstract

The present research investigates the effectiveness of using unidirectional carbon fiber reinforced polymer as an external strengthening technique to increase the load carrying capacity of existing reinforced concrete corbels subjected to monotonic or non-reversed repeated loads. 20 normal weight reinforced concrete double-sided corbels were cast for this purpose, 15 of them were strengthened with carbon fiber strips. The variables studied were: the width and orientation of carbon strips and the load history schemes used to apply the non-reversed repeated loading. It was found that the external strengthening with carbon strips improved the capacity of corbels. The enhancement in the load carrying capacity for the corbels strengthened with 50 mm strips and tested under monotonically loads were 11%, 15% and 27% for the horizontal, inclined and mixed orientations respectively. While for the non-reversed repeated loaded corbels, the enhancement in the load carrying capacity was about 11%, 18% and 21% for the horizontal, inclined and mixed orientations respectively.

Keywords

• normal reinforced concrete corbels
• external strengthening
• unidirectional reinforced carbon fiber fabric
• epoxy bonding