Erosive Degradation Study of Concrete Augmented by Mussel Shells for Marine Construction

Abstract

This work proposes a green material for artificial reefs to be placed in Galicia (northwest Spain) taking into account the principles of circular economy and sustainability of the ecosystem. New concrete formulations for marine applications, based on cement and/or sand replacement by mussel shells, are analyzed in terms of resistance to abrasion. The interest lies in the importance of the canning industry of Galicia, which generates important quantities of shell residues with negative environmental consequences. Currently, the tests to determine the abrasion erosion resistance of concrete on hydraulic structures involve large and complex devices. According to this, an experimental test has been proposed to estimate and compare the wear resistance of these concretes and, consequently, to analyze the environmental performance of these structures. First, a numerical analysis validated with experimental data was conducted to design the test. Subsequently, experimental tests were performed using a slurry tank in which samples with conventional cement and sand were partially replaced by mussel shell. The abrasive erosion effect of concrete components was analyzed by monitoring the mass loss. It shows an asymptotic trend with respect to time that has been modeled by Generalized Additive Model (GAM) and nonlinear regression models. The results were compared to concrete containing only conventional cement and sand. Replacing sand and/or cement by different proportions of mussel shells has not significantly reduced the resistance of concrete against erosive degradation, except for the case where a high amount of sand (20 wt.%) is replaced. Its resistance against the erosive abrasion is increased, losing between 0.1072 and 0.0310 wt.% lower than common concrete. In all the remaining cases (replacements of the 5–10 wt.% of sand and cement), the effect of mussel replacement on erosive degradation is not significant. These results encourage the use of mussel shells in the composition of concrete, taking into account that we obtain the same degradation properties, even more so considering an important residue in the canning industry (and part of the seabed) that can be valorized.

Application of residuals from purification of bivalve molluscs in Galician to facilitate marine ecosystem resiliency through artificial reefs with shells – One generation

“…The incorporation of calcite and aragonite shells contribute to creating a dense calcium carbonate protective layer along the concrete's surface. This layer provides protection against chemical attacks from seawater (Camba et al, 2021). An important conclusion that can be extracted from the results is that the water absorption is lower when the medium arid is substituted, and when calcite predominates over aragonite.…”

Biological and Hydrodynamic Aspects for the Design of Artificial Reef Modules for Cephalopod Molluscs in the Ares-Betanzos Estuary

“…Cephalopods play a crucial role in Galicia [16][17][18][19]. The species with the greatest socioeconomic impacts on the Iberian Peninsula are the common octopus (Octopus vulgaris), cuttlefish (Sepia officinalis), and squid (Loligo vulgaris) [20].…”

Full-Field Deformation-Aided Compressive Failure Evaluation of Seawater Concrete Using Digital Image Correlation Technique

“…Besides, the use of seawater-based concrete has been considered as an effective approach to sustainable development in construction engineering where the construction materials and freshwater are inconvenient to access [1][2][3]. In this regard, the mechanical properties of newly developed seawater-based concrete in specific service conditions have become a source of concern due to the fact that some inorganic ions in seawater cause remarkable changes to the microstructure of concrete [3][4][5][6]. It has been reported that the introduction of seawater could lead to gains in early strength and shortening of solidification time of seawatermixed concrete, which is probably caused by the accelerated hydration process induced by the presence of chloride ions in seawater [7,8].…”