Bio-colonization layered concrete panel for greening vertical surfaces: A field study

Although the economical and aesthetical benefits of living walls are well recognized, the practical application of such systems is still under consideration. In addition, high installation and maintenance costs of existing living wall systems hinder the greening of the urban environment. This case study investigates two prototype series of living layered concrete (LLC) wall panels that require minimal maintenance, focusing on the natural colonization of wall segments and supplying water without additional nutrients. The panel design accelerates non-vascular plants’ natural colonization of vertical surfaces and transforms rare luxurious greening systems into typical projects. An innovative degradable material, a bio-booster simplifies the production technology and ensures the wall panel’s natural bio-colonization and sustainable greening, besides the exceptional architectural appearance of the exterior surface. The panel comprises two layers: (1) a pervious lightweight concrete layer featuring high porosity, permeability, and bio-receptivity, and (2) a high-performance fiber-reinforced concrete layer, which ensures the structural integrity of the panel segment. This case study reports the results of ongoing field tests on 16 prototypes installed in March 2021 and April 2023. The long-term field tests of LLC wall panel prototypes in Northern Europe climatic conditions proved the plants’ survival and growth performance—non-vascular plants colonized most of the pervious concrete two years after the installation in 2021. The long-term greening results and physical tests of the pervious and high-performance concretes allowed further optimizing the LLC system for the second-stage field tests in 2023.