Monitoring of FRP Strengthened bridges

The strengthening of existing structures requires that composite materials maintain unchanged their characteristics and their load bearing capacity at all times. This in turn requires a program of monitoring intervention post application to ensure their effectiveness. This activity can be scheduled.

Until today, due to the lack of data concerning the long term ageing behaviour of these materials, monitoring activity is not yet clearly defined both for timescale and for methodology. The aim of this work is to identify the different typologies of damage on the composite material and on the interface composite-substrate, to find the most appropriate repair technique. In fact periodical Non-destructive Testing (NdT) and Structural Health Monitoring (SHM) can provide a suitable level of confidence on the durability of such applications, and therefore they are to be considered an effective solution to the problem.

This paper presents and classifies techniques and protocols necessary for the best monitoring of structures strengthened with FRP. In particular destructive and non-destructive control techniques, damage typologies and repair techniques.

This paper also describes the monitoring work carried out on the “ponte della Corona”, a cast iron footbridge in Venice (Italy), repaired and strengthened with Aramid Fiber Reinforced Polymer (AFRP) in 2002.