Old concrete floors strengthened to withstand earthquakes

Researchers have developed technology to strengthen concrete flooring in older buildings to make them resistant to earthquake damage.

Many buildings recently constructed in regions with a high earthquake risk have strengthened concrete flooring that is designed to withstand stress caused by earthquakes, but buildings constructed in the 1980s and 1990s often have weaker floors. An earthquake can result in older reinforced concrete flooring collapsing and becoming detached from the supports, resulting in the building falling. Up until now, there has been no simple or cost-effective way to reinforce older floors.

A team from Canterbury and Auckland universities in New Zealand has found a solution to this issue. They made a precast concrete floor in the lab and tested it with various cable and beam reinforcements until they found the configuration that adequality protects the floor. Commenting on the research, the vice presided of the Structural Engineering Society, Nicholas Brooke, said:

“We now believe we are in a position where we have reliable guidance that engineers should have confidence in to set out how to go about designing those retrofits and ensuring that they’re installed properly.”

Earthquake strengthening for buildings with precast floors is expensive. It cost about £92m to strengthen Wellington Town Hall in New Zealand. Some building owners in earthquake zones decide to demolish buildings rather than spend a lot of money to save them. The retrofit concrete flooring technology the researchers developed is more cost-effective and should save more buildings from being demolished.