Development of material monitoring protocols for nature-inclusive designed concrete units in harbor-fronts

Abstract

Abstract Human activities are putting stress on earth’s ecosystems, and with increasing populations in coastal zones, the pressure on the marine environments intensifies. To accommodate the increase in anthropogenic activities in these areas, concrete is often used to adapt the coast to human requirements. By mimicking nature-inspired substrates, ecologically designed concrete aims to facilitate biological growth, thereby increasing biodiversity and enhancing the local marine ecosystem. As this practice becomes more frequently applied, a need for material monitoring protocols fitted towards these designs arises. Reinforced concrete exposed to marine environments is subjected to an increased risk of corrosion due to the aggressive nature of seawater and environmental conditions that affect concrete. Material monitoring/testing of concrete used in infrastructure is essential to understand the state of structural integrity. However, when using nature-inclusive designs that differ from the classically designed grey concrete with a smooth surface structure, there are no standards in place for monitoring these structures and their potential positive interaction with biogenic layers. In this study, we present a multi-method monitoring protocol developed based on our experiences with nature-inclusive designs on concrete used in a pilot project in a Spanish harbor front and discuss potential further developments of these types of protocols. The protocol includes methods that investigate mechanical properties, transport rates, mineralogical changes, and density/porosity. The complex surface structure, the different densities of the material and small size of the units tested presented several challenges and limitations for commonly applied assessment methods, which require additional steps and creative solutions to gain reliable results.