SWConsult were engaged on this project to assess a steel framed concrete pre-cast panel system which covered the entire external facade of the building and had also been used internally in areas. The panels had started to visibly deteriorate. We concluded this was due to the presence of magnesium oxychloride in the pre-cast panels which in damp conditions the chloride ions are able to migrate to the steel work and form ferric chloride (rust). Ferric chloride is hygroscopic and is able to suck moisture out of the atmosphere exacerbating and substantially accelerating the corrosion. This not only degrades the buildings appearance from an architectural standpoint but is also a serious structural concern as the weatherproofing qualities of the cladding is compromised which will inevitably result in interior damp but more severely, corroded reinforcement within structural walls. Failure to remediate the problem quickly will result in structural failure of structural walls.
SWConsult provided design input into the rectification procedure. We now have a method in place to resolve the serious structural defect.
Photo 1 – Pre-cast panel system deteriorating exposing structural concrete
Photo 2 – Pre-cast panel removed exposing corroded reinforcement within the panels due to water ingress
Photo 3 – PFC flange which formed part of the panel cut back, concrete removed 30mm deep
Photo 4 – Monolithic bonded concrete repair carried out to 20mm thickness to re-instate the original profile together with rendered painted finish typical of entire prototype work