Strengthening of reinforced concrete beams using ultra high performance fibre reinforced concrete (UHPFRC)

In this study the efficiency of the use of Ultra High Performance Fibre Reinforced Concrete (UHPFRC) for the strengthening of existing Reinforced Concrete (RC) beams has been investigated. Experimental work has been conducted to determine UHPFRC material properties. Dog-bone shaped specimens have been tested under direct tensile loading, and standard cubes have been tested in compression. These results have been used for the development of a numerical model using Finite Element Method. The reliability of the numerical model has been validated using further experimental results of UHPFRC layers tested under flexural loading. Further numerical study has been conducted on full-scale beams strengthened with UHPFRC layers and jackets, and these results were compared to respective results of beams strengthened with conventional RC layers and with combination of UHPFRC and steel reinforcing bars. Superior performance was observed for strengthened beams with UHPFRC three side jackets, and the efficiency of this technique was highlighted by comparisons with other strengthening techniques

Strengthening of reinforced concrete beams: RC versus UHPFRC layers

Strengthening of Reinforced Concrete (RC) beams is of high importance for the structural upgrade of existing buildings. The majority of the existing RC structures need to be upgraded either because they are designed with old or without seismic code provisions or because of existing damages. In this study the effectiveness of the use of traditional RC layers is compared with the use of Ultra High Performance Fibre Reinforced Concrete (UHPFRC) layers. Experimental investigation has been conducted on beams strengthened with these two techniques and the effectiveness of the examined methods has been evaluated via comparisons of the load-deflection and the interface slip results