Automated Design Guidance for the Repair & Retrofit of Concrete Bridge Structures with Frp

1.1 Background Fibre Reinforced Polymers (FRP’s) have seen active use for strengthening applications in construction since the late 1980’s. They are now securely placed to replace the ageing technologies used in the commonly termed, ‘traditional methods’ of strengthening, which have customarily resulted in an increased cross-section size with the provision of additional reinforced concrete, or ‘dowelling-in’ additional reinforcement. Although readily accepted by approval authorities, having been widely tried and tested, lengthy loading restrictions to allow for curing of the concrete to adequate strengths can render many options impractical. Steel as a strengthening material, became more widely used, post 1960, traditionally fixing plates to the concrete substrate in tensile zones for flexural applications, or using external straps for shear strengthening. Mechanical, bolted anchorage can cause consequential damage to embedded reinforcement and hence more recently, epoxy based resin bonding has been introduced, launching development and advancement of FRP technologies, initially adopted as a direct steel replacement. In the majority of cases, steel is surpassed in measures of performance by FRP, offering comparable repair functions.