Otello Bergamo, Gaetano Russo and Stefano Donadello, Italy

The Outstanding Paper Award is remitted each year to the author(s) of a paper published in the preceding year’s issues of the IABSE quarterly Journal Structural Engineering International (SEI), encouraging and rewarding contributions of the highest quality. The Award is presented in the categories ‘Scientific Paper’ and ‘Technical Report’.

IABSE has awarded the Outstanding Paper Award 2014 in the category ‘Scientific Paper’:
“Retrofitting of the Historic Castagnara Bridge in Padua, Italy, with Fibre Reinforced Plastic Elements" by Otello Bergamo, Gaetano Russo and Stefano Donadello, Italy, SEI 4/2014 (November) pp. 532-543.

Masonry arch bridges are typically historical infrastructures that were often not designed to withstand the heavy truck traffic that they are currently carrying and therefore must be replaced by modern concrete or steel bridges. Usual methods of strengthening masonry bridges are neither simple nor economical. This paper investigates whether the application of composites in the form of either a fabric wrap or laminate strips to masonry constructions may increase the load-bearing capacity of these structures. This research project demonstrates how advanced composite materials can be used to strengthen existing masonry arch bridges in order to increase their load-bearing capacity.

This paper details the methodology adopted to retrofit and repair the Castagnara masonry bridge in Padua (Italy) and the investigations related to the damage of the bridge, the retrofitting by fibre reinforced plastic (FRP) elements and the results of the consolidation. Retrofitting involves the insertion of a prestressed steel cable into the abutments, consolidating injections, bonding by FRP strips on the extrados of the deck and demolition and reconstruction of the reinforced concrete slab. Linear-elastic and non-linear dynamic analysis of the bridge have been performed. Detailed finite element models (FEM) and on-site dynamic acceleration measurements were used to evaluate retrofit performance. Results show that applying carbon fabric to the masonry bridges provides significant increases in bending and shear capacity. However, a statistically significant number of masonry structures strengthened with carbon fibres need to be tested to arrive at definitive stress modification factors.