Shear Behaviour of RCC Beams Retrofitted with Ultra High Performance Concrete

The main contributing factors are change in their use new design standards, deterioration due to corrosion in the steel caused by exposure to an aggressive environment and accident events such as earthquakes. In such circumstances there are only two possible solutions: replacement or retrofitting. Full structure replacement might have determinate disadvantages such as high costs for material and labour, a stronger environmental impact and inconvenience due to interruption of the function of the structure. Whenever possible, it is often better to repair or upgrade the structure by retrofitting or strengthening. In this study, shear behaviour of reinforced concrete beams retrofitted with Ultra High Performance Fibre Reinforced Concrete (UHPFRC) with two types of fibres (crimped and micro steel fibre) and a plain UHPC were compared with control beams. A normal M20 mix was designed for the study. Two point loading system was adopted for the test. And deflection were noted for each load increment. Behaviour of retrofitted beams and control beams were studied by comparing the properties such as first crack load, ultimate load and load deflection plot. The result showed that shear performance was improved by 88% for UHPFRC-C, 78% for UHPFRC-M and 36% for UHPC, showing the effect of fibres which improved the shear performance of UHPFRC retrofitted beams.