Materials

Earthquake-resistant concrete keeps walls from falling

Plans call for EDCC to sprayed onto existing walls as part of a seismic retrofit
Plans call for EDCC to sprayed onto existing walls as part of a seismic retrofit
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An unprotected wall (left) and one coated with EDCC (right)
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An unprotected wall (left) and one coated with EDCC (right)
Plans call for EDCC to sprayed onto existing walls as part of a seismic retrofit
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Plans call for EDCC to sprayed onto existing walls as part of a seismic retrofit

While we may hear about ways of constructing new buildings to make them earthquake-resistant, what about all the buildings that are standing already? Well, that's where a new concrete developed at Canada's University of British Columbia (UBC) comes in. Sprayed onto existing walls, it reportedly allows them to withstand tremors that would otherwise reduce them to rubble.

Known as eco-friendly ductile cementitious composite (EDCC), the concrete contains polymer-based fibres. These give it a strong-yet-malleable quality not unlike steel, which tends to flex under pressure instead of crumbling like traditional concrete.

Additionally, almost 70 percent of the cement in the material is replaced with an industrial byproduct – flyash. This is what makes it eco-friendly, as cement production is a major source of greenhouse gas emissions, plus the flyash would likely otherwise end up just being dumped.

An unprotected wall (left) and one coated with EDCC (right)
An unprotected wall (left) and one coated with EDCC (right)

In lab tests, a 10 mm-thick layer of EDCC was applied to walls made of traditional concrete blocks, which were then subjected to simulated tremors of a 9.0 - 9.1 magnitude – that's the same as the earthquake that struck Tohoku, Japan in 2011. The walls held up, while their uncoated counterparts collapsed.

Plans now call for the first real-life application of the technology to occur within the next couple of months, as EDCC is applied to the walls of Vancouver's Dr. Annie B. Jamieson Elementary School. The UBC-hosted Canada-India Research Centre of Excellence is also making the material available for the seismic retrofitting of a school in northern India.

There's more information in the video below.

Source: University of British Columbia

UBC researchers develop earthquake-resistant concrete

6 comments
aki009
That is really cool. But it should be noted that flyash can concentrate radioactive elements that are naturally present in coal by a factor of 10. That's not bad in itself, but the area being treated with this stuff should be well ventilated to avoid radon buildup.
Allard
What about the pressure from the roof? Will the roof not collapse if the walls shake like in the video?
Terence Hawkes
This is a fabulous idea. In earthquake prone zones which traditionally seem to use a lot of concrete construction, this would be extremely beneficial. I am thinking about places like Turkey.
DavidB
My first question when I heard about this product on public radio, this morning, was whether the building remains usable after enduring such a seismic event, or the product is intended only to offer occupants the opportunity to survive the quake and get out of the building, which would then need to be demolished and replaced.
NoelFrothingham
Allard, proper roof structure attachment to the structure upon which it is supported will keep it from collapsing in most cases - emphasis on 'most'.
Madlyb
I would like to see this compared to fiberglass reinforced wall coatings that have been around for decades.
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