A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Durability of Innovative Cementitious Coatings for Concrete Wastewater Treatment Plants: Impact of Cracks on Biodeterioration
Calcium aluminate-based materials have shown high resistance to the chemical and biological attack in sewer systems and thus are used to protect Portland cement-based structures and increase their durability. In this direction, a protective calcium aluminate-based coating, designed to be sprayed in a thin layer onto newly built wastewater infrastructures, was developed by Imerys Aluminates. The question arises of the ability of the coating to maintain its protective function when a crack is initiated in the concrete support and possibly propagates into the coating. Several phenomena may develop and condition the behavior of the cracked aluminous coating, including the self-healing of the cementitious material and the penetration of micro-organisms to reach the substrate. To study this coupling of cracking and biodeterioration in the lab, a method for the generation of representative cracks was developed. The three-point bending test was performed on these coated mortars to initiate cracks with a specific opening width, to be maintained after unloading. Then, to understand the mechanisms of biodeterioration, cracked and uncracked specimens were exposed to the BAC test which reproduces biodeterioration conditions observed in sewer environments. The biodeterioration process was monitored in terms of analyses of the composition of the leached solutions to quantify the calcium and aluminum leaching. The superior resistance of the coated substrates was significantly proven. The presence of a crack in the coated substrates has no influence on the leaching species for the specific duration of the test.
Durability of Innovative Cementitious Coatings for Concrete Wastewater Treatment Plants: Impact of Cracks on Biodeterioration
Calcium aluminate-based materials have shown high resistance to the chemical and biological attack in sewer systems and thus are used to protect Portland cement-based structures and increase their durability. In this direction, a protective calcium aluminate-based coating, designed to be sprayed in a thin layer onto newly built wastewater infrastructures, was developed by Imerys Aluminates. The question arises of the ability of the coating to maintain its protective function when a crack is initiated in the concrete support and possibly propagates into the coating. Several phenomena may develop and condition the behavior of the cracked aluminous coating, including the self-healing of the cementitious material and the penetration of micro-organisms to reach the substrate. To study this coupling of cracking and biodeterioration in the lab, a method for the generation of representative cracks was developed. The three-point bending test was performed on these coated mortars to initiate cracks with a specific opening width, to be maintained after unloading. Then, to understand the mechanisms of biodeterioration, cracked and uncracked specimens were exposed to the BAC test which reproduces biodeterioration conditions observed in sewer environments. The biodeterioration process was monitored in terms of analyses of the composition of the leached solutions to quantify the calcium and aluminum leaching. The superior resistance of the coated substrates was significantly proven. The presence of a crack in the coated substrates has no influence on the leaching species for the specific duration of the test.
Durability of Innovative Cementitious Coatings for Concrete Wastewater Treatment Plants: Impact of Cracks on Biodeterioration
RILEM Bookseries
Beushausen, Hans (editor) / Ndawula, Joanitta (editor) / Alexander, Mark (editor) / Dehn, Frank (editor) / Moyo, Pilate (editor) / Hoballah, Reem (author) / Peyre Lavigne, Matthieu (author) / Toumi, Ahmed (author) / Lacarriere, Laurie (author) / Patapy, Cédric (author)
International Conference on Concrete Repair, Rehabilitation and Retrofitting ; 2024 ; Cape Town, South Africa
2024-11-01
12 pages
Article/Chapter (Book)
Electronic Resource
English
THE DURABILITY OF INNOVATIVE CEMENTITIOUS COATINGS: PHOTOCATALYTIC ACTIVITY AND COLOUR
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