Loading ...Depending on how well the concrete is poured, and the quality of the mix, reinforced concrete can last up to a hundred years. Or as little as twenty, especially by the sea. Water eventually seeps in, rusts the rebar which expands and cracks the concrete. If salt water seeps in then the process is vastly accelerated. Some friends own a condo up the coast, on the seafront. Third, top storey. After they bought it they realised that they were not allowed to make any external repairs, or even paint it outside, it had to be done by the body corporate. And if the BC wanted it done, they had no option. Initially they were not happy (they had a leaky window frame, a bit of bog should stop it, but it was $’000s for a professional job – keep the water out of the building structure, not just out of the condo), but then I pointed out the almost identical block next door where the concrete cancer was all too clear. One set of external stairs had already been replaced. All the balconies had chunks of concrete falling off the underneath, and you could see the rusty rebar, or what was left of it. You could see where rust in the bottom balcony had pushed the pillar upwards so that the top balcony was an inch higher at the front than the back. How you repair a balcony when it’s poured as part of the floor, I don’t know, but they’ve now done it and I’m guessing $$$$ were a big part of the answer. Age about 45 years.
Of course, this is only the concrete you can see. You can only maintain the concrete you can see, and access. If you want to check a condo out, start in the underground carpark around the bases of the pillars.
One hundred years. Condos, tower blocks, bridges, tunnels, dams. And if you’re wondering how all those Roman concrete buildings are still standing, e.g. the Pantheon – no rebar. Proper engineering.