The Italian engineer who designed the Genoa bridge that collapsed and killed 43 people warned of the risk of corrosion four decades ago, it has emerged.
Riccardo Morandi wrote a report in 1979 recommending constant maintenance of the structure to remove all traces of rust and fill in exposed patches on the reinforcements.
The report produced 12 years after the bridge bearing his name was opened referred to a “well-known loss of superficial chemical resistance of the concrete” because of sea air and pollution from a nearby steel plant.
Mr Morandi, who died in 1989, insisted the reinforced concrete bridge design was sound but noted the “aggressivity” of the corrosion that was not seen in similar structures in different environments.
He warned: “Sooner or later, maybe in a few years, it will be necessary to resort to a treatment consisting of the removal of all traces of rust on the exposure of the reinforcements, to fill in the patches.”
The engineer recommended using an epoxy resin to cover the reinforcements with materials “of a very high chemical resistance”.
Excerpts from the report were broadcast on RAI state television on Sunday and published online.
A huge section of the bridge collapsed on 14 August during a fierce storm, killing 43 people and forcing the evacuation of nearby residents in the densely built-up area.
The cause is under investigation, and a team of engineers appointed by the ministry of infrastructure and transportation carried out a preliminary inspection Sunday after rescue crews concluded their search for the missing.
Roberto Ferrazza, the head of the government team, said the preliminary survey suggested a series of possible causes and not just a simple collapse of the bridge support.
“We have to look at the positioning of the rubble, considering that there was a break that provoked an imbalanced movement of the structure,” Mr Ferrazza was quoted as saying by the ANSA news agency.
Mr Ferrazza was one of the engineers who knew about the advanced corrosion underway on the key bridge support that gave way, according to L’Espresso magazine. He attended a meeting of experts from the transport ministry and the company that manages bridge repairs on 1 February.
Minutes of the meeting, which bear Mr Ferrazza’s signature, recommended that the supports be reinforced given the “trend of degradation” being registered.
Bidding opened in April for the €20m (£18m) public works contract to do the work, according to Italian media.
The Morandi Bridge was a key artery that linked highways to Milan and France, a vital lifeline for both commercial traffic as well as vacationers bound for the mountains and Mediterranean beaches.
Engineers say there have long been concerns about its unusual concrete-encased stay cables, which Morandi used in several of his bridge designs instead of the more common steel cables.
Dozens of Genoese residents gathered in a central piazza on Sunday evening to vent rage and pain over the collapse. Many wrote messages and poems on sheets of white paper unrolled on the piazza cobblestones.
“This way everyone can write whatever he or she thinks without necessarily shouting or screaming at a time when all we need is silence,” said Elisa D’Andrea, one of the event organisers.
The families of those killed in the Genoa bridge collapse shouted and jeered at members of Italy’s former government at a state funeral for the victims on Saturday.
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