Architecture

“Biological concrete” promotes vertical gardens

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Biological concrete panels
Biological concrete panels
Biological concrete panels
Lichens growing on rock are similar to how biological concrete works
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An ivy covered building is a lovely thing, but ivy roots can rip into brickwork and the vines are a highway for vermin looking for a way inside. Modern vertical gardens try for the same aesthetic effect with some added environmental advantages, but they’re often complicated things full of hydroponics gear and difficult to maintain. An alternative is being developed at the Structural Technology Group, Universitat Politècnica de Catalunya, Barcelona, where a team led by Antonio Aguado has come up with a “biological concrete” designed to act as a substrate for vertical gardens that is simple, low maintenance and requires little or no attention.

The key to biological concrete is that it replaces the Portland cement normally used with magnesium phosphate cement – a quick-setting cement often used for repair work. In biological concrete, the magnesium phosphate makes the concrete slightly acidic. This makes it an excellent environment for microalgae, fungi, lichens and mosses in Mediterranean climates. The parameters used in making the biological concrete are adjusted for the desired level of porosity and surface roughness to encourage colonization.

The biological concrete is used in constructing vertical garden panels made in three layers. These consist of a waterproof layer that sits against the side of a new or existing building, a middle layer that retains water and an outer layer that permits water in, but prevents it from escaping. This means that the panels can be used as vertical gardens without mechanical apparatus or constant maintenance.

Biological concrete panels

The idea behind these panels is that they accumulate rainwater and become an ideal environment for mosses and other simple organisms, which should appear within a year of installation. Over time, the population on the panel will evolve and the colors and patterns on the panel with slowly change. The panels are also designed to discourage plant growth in order to prevent root damage.

The purpose of the panels is mainly aesthetic, but the team also says that the growths on the panels can act as insulating material and a thermal regulator. They also say that the colonies help reduce carbon dioxide, though they don’t say by how much. Unless the colonies are amazingly heavy, it’s probably negligible.

Source: UPC

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7 comments
Derek Howe
who would want a brand new building that instantly looks like a dilapidated building
Chris D
Whether this new biological concrete will be able to be used on older builds will depend on the additional weight gained through its own mass as well as the weight of water and plant life it sustains. To have this greenery would be lovely but one would not want to have it creating structural performance problems (would give green walls a bad name).
Calvin k
the question is the longevity of the material, even without root damage. In ecological succession moss and lichens are often the first to break down the rocky terrains for later plants... so I imagine they still have some impact. Although being slightly acidic it should be more resistant to acid rain.
Mindbreaker
It is interesting and I hope it works. Somehow, I think there may be some issues: Moisture seal with the wall and possible mildew, and possible accelerated disintegration. Lichens digest rock, slowly but surly. Maybe you need an easy way to replace panels?
packoftwenty
What an incredibly beautiful building in the first picture! Must have taken minutes to design...
Gannet
Boston ivy does not go after the lime, so is safe for walls / brickwork.
NatalieEGH
On building plans are one of the main causes of breakdown but another possibly greater problem is freezing of water. I would expect this might be a good idea in areas where freezing does not happen or at best infrequent.
I am not sure how lichen, moss, and similiar plants break down stone whether is simple mechanical methods or chemical processes also. I would hope the engineers have this latter type of breakdown accounted for.
As to appearing old Derek Howe said, that is more we are not used to seeing something like that except of old building. If it were common, we would not associate moss covered with old.