Vertical gardens and green walls are beautiful and environmentally friendly means of adding a little life to architecture – but until now, most required structural foundations to help attach the plants and soil to the building. Now, a group of researchers led by Antonio Aguado, Ignacio Segura, and Sandra Manso at the Structural Technology Group of the Universitat Politècnica de Catalunya has developed a new multilayer concrete that is able to support plant life. Both a medium for growth and a construction material, the system allows for thermal regulation and CO2 sequestration.
Created for a Mediterranean climate, the biological concrete is composed of three layers placed on a structural base. The first is a waterproofing layer on top of the structural foundation which protects against moisture damage. The next is the biological layer which supports colonization of organisms like moss, lichen, and drought-tolerant vegetation and acts as an internal microstructure that also aids in water retention. The last layer is a discontinuous coating with a reverse waterproofing that allows water to seep through and keep it inside the concrete.
Aside from being a novel way to renovate a home, the concrete has applications in air purification and CO2 reduction. It can absorb solar radiation, helping to regulate temperature inside the building. Forming what the team describes as a “living painting”, the ever-changing biological layer is an alternative to static and toxic paints. Without the need for supporting structures, vertical gardens made with the composite are simpler and cheaper to build or augment existing facades. Currently, the biological concrete is being tested at at the UPC and the University of Ghent (Belgium), and is in the process of a patent application. Soon, we may see many more buildings sprout gardens with an innovation that simplifies the greening process.
Images via Universitat Politecnica de Catalunya and Wikimedia Commons user Ericd