Electrochemical limestone synthesis in seawater binds metal grids and sediments for coastal protection
- PDF / 1,421,159 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 56 Downloads / 174 Views
ORIGINAL PAPER
Electrochemical limestone synthesis in seawater binds metal grids and sediments for coastal protection Charlotte Carré1,2 · Alaric Zanibellato1 · Nesrine Achgare1 · Pierre‑Yves Mahieux2 · Philippe Turcry2 · Marc Jeannin2 · René Sabot2 Received: 20 February 2020 / Accepted: 24 May 2020 © Springer Nature Switzerland AG 2020
Abstract Coastal erosion is accelerating due to global warming, thus weakening infrastructures and threatening the population. Actual remediation techniques are costly, resource-consuming and vulnerable. Here, we designed the synthesis of a carbonate rock by seawater electrolysis to reinforce engineering infrastructures. Inspired by electrochemical cathodic protection, the new technique involves the application of a low current in a buried metal grid to precipitate aragonite ( CaCO3) and brucite (Mg(OH)2), which agglomerate the metal grid with the sediment. We tested the effects of power surface densities, 3 and 5 W/m2, on agglomerate properties during more than 2 years in natural conditions. We measured agglomerate thickness, accessible water porosity and axial compressive strength. The results show growth rates of 2.5 mm/month at 3 W/m2 and 4.1 mm/month at 5 W/m2 during the first 32 months. Data on material properties do not show a significant effect of power surface density. Maximum porosity of 16% is reached after 12 months, and maximum compressive strength of 10 MPa is obtained after 18 months. Overall, our findings confirm under outdoor conditions the practical application of electrochemical limestone synthesis for reinforcement of the coastal infrastructures. Keywords Coastal protection by cathodic prevention · Calcareous deposit agglomerates · Growth kinetics · Physical and mechanical properties · Thickness · Water-accessible porosity · Axial compressive strength
Introduction In recent years, there has been a dramatic increase in coastal erosion as a result of the gradual rise in oceans and severe weather events. Data have shown a clear trend in the global increase in average ocean temperatures, melting of snow and ice, and average sea level during the 20th century (IPCC (Intergovernmental Panel On Climate Change) 2007). On a global scale, between 1984 and 2015, the loss of permanent land in coastal areas amounts to almost 28,000 km2 (Mentaschi et al. 2018). The French coast is particularly affected with 30 km2 lost over 50 years, with dunes retraction, shrinking beaches, and cliffs, and dikes collapse (Genter et al. * Pierre‑Yves Mahieux pierre‑yves.mahieux@univ‑lr.fr 1
Géocorail SAS, 4 rue Gaston Castel, 13016 Marseille, France
Laboratoire des Sciences de l’Ingénieur pour l’Environnement, LaSIE UMR-CNRS-7356 - La Rochelle Université, La Rochelle, France
2
2004; Brunel and Sabatier 2009; Ministère de la transition écologique et solidaire 2017). With up to 12% of the population living in these sensitive areas (Béoutis et al. 2004), coastal erosion could cause significant damage to urban infrastructure and trigger climate migrations (Adger et al. 2005). Del
Data Loading...
