Ruben Paul Borg (University of Malta)
Nature-based solutions (NBS) are actions intended to protect, manage in a sustainable manner, and restore ecosystems to address societal challenges including those related to climate change and disaster risks. By working with nature rather than against it, these strategies provide dual benefits for both human well-being and biodiversity. NBS integrate ecosystems into critical infrastructure planning. By protecting or restoring natural features such as coastal areas, valleys and urban green areas, NBS shield essential systems from hazards like flooding and heatwaves while providing long-term ecological and economic resilience.
The Construction Materials Engineering and Structural Monitoring research team at the Faculty for the Built Environment, University of Malta is a partner in the NBSINFRA Research Project which operates under the European Union’s Horizon Europe Program Grant Agreement No. 101121210. The project, launched in 2023, focuses on integrating Nature-Based Solutions to protect critical urban infrastructure against hazards. The project establishes a collaborative consortium of 18 partners across 10 countries including Malta, to develop scalable, budget-friendly resilience metrics and digital twin frameworks.
The University of Malta team investigated the integration of NBS in concrete coastal infrastructure as a hybrid solution, to enhance both structural performance and marine biodiversity. Seawalls and breakwaters are considered as examples of traditional grey coastal defence elements that prioritise protection and durability but frequently disturb natural ecosystems and are not adaptable to climate change. NBS presents sustainable solutions, integrating engineering performance with ecological sensitivity. Eco-concrete mixes were designed, developed, tested and eventually monitoring to assess the materials engineering properties and also their ecological performance in enhancing biodiversity, when used in coastal engineering structures and reef regeneration. Cast concrete and 3D concrete printed elements were developed and assessed. The eco-concrete mixes were developed as advanced cement-based mixes with different ingredients, intended for aggressive coastal environments. The material performance was determined through an extensive experimental investigation, including fresh concrete properties, mechanical properties and long-term durability performance to ensure the performance of coastal structures, together with leaching tests. Field monitoring of the different concrete types was carried out on samples exposed to a marine environment, in order to evaluate biological growth over time for different concrete mix compositions, including low carbon eco-concrete, and test parameters: porosity, surface texture, orientation and other parameters. Samples were subjected to both simulated and actual seawater conditions, respectively at sea water tanks set up at Aquatic Resources Malta (ARM), and at Portomaso in St Julians Malta. Facilities at ARM allowed continual flow of seawater in outdoor tanks, creating optimal conditions for colonisation of concrete structures without disturbance or natural grazing.
The research activity demonstrated that Eco-concrete mixtures can strike a balance between ecological performance and engineering properties including mechanical performance and long-term durability. Low-carbon concrete encouraged more marine biodiversity and together with surface roughness encouraged regeneration without compromising on the engineering properties required in coastal critical infrastructure. Biodiversity growth and regeneration is assessed with the collaboration of the Department of Geoscience’s marine group, Faculty of Science.
Hybrid Nature Based Solutions in coastal infrastructure and reef regeneration, promote more environmentally integrated, robust, and sustainable solutions encouraging biodiversity and ecosystem regeneration. The project activity at the University of Malta, sets the scene for the future deployment of Hybrid NBS in critical infrastructure in coastal areas in Malta, together with reef regeneration in the Maltese Islands. For further information contact the NBSInfra HORIZON Europe Project Principal investigator and main contact, Prof. Ruben Paul Borg ruben.p.borg@um.edu.mt