RESEARCHERS AT the UK's Cambridge University are developing a new form of bridge strengthening technique which should offer a more convenient alternative to traditional steel plate reinforcement.
The new method uses pretensioned carbon fibre reinforced plastic (CFRP) tape wrap to boost the shear resistance of under-reinforced concrete beams and columns.
Bonding CFRP plates and mats to understrength beams to increase their flexural strength has become widely used in the last five years. The UK Highways Agency approved the technique for highway structures in 1999.
But Cambridge University structural engineer Dr Janet Lees said little work had been done to model of CFRP reinforcement when used to increase shear resistance. 'We will assess the performance.
This will include its resistance to fatigue, ' she said.
The two year programme is supported by Swiss federal testing authority EMPA and a US$48,000 Royal Society Award.
Lees said the team will use imaging techniques to monitor crack propagation and improved data logging to pick up changes in stiffness with time.