Impact of the urban heat island on freeze-thaw risk of natural stone in the built environment, a case study in Ghent, Belgium

Daphne Guilbert; Steven Caluwaerts; Klaas Calle; Nathan Van Den Bossche; Veerle Cnudde; Tim De Kock

doi:10.1016/j.scitotenv.2019.04.344

Impact of the urban heat island on freeze-thaw risk of natural stone in the built environment, a case study in Ghent, Belgium

Sci Total Environ. 2019 Aug 10:677:9-18. doi: 10.1016/j.scitotenv.2019.04.344. Epub 2019 Apr 24.

Authors

Daphne Guilbert¹, Steven Caluwaerts², Klaas Calle³, Nathan Van Den Bossche³, Veerle Cnudde⁴, Tim De Kock⁴

Affiliations

¹ Architecture and Urban Planning, Department of Engineering and Architecture, Sint-Pietersnieuwstraat 41 B4, 9000 Gent, Belgium. Electronic address: daphne.guilbert@ugent.be.
² Atmospheric Physics, Department of Physics and Astronomy, Ghent University, Krijgslaan 281 S9, 9000 Gent, Belgium.
³ Architecture and Urban Planning, Department of Engineering and Architecture, Sint-Pietersnieuwstraat 41 B4, 9000 Gent, Belgium.
⁴ PProGRess, Department of Geology, Ghent University, Krijgslaan 281 S8, 9000 Gent, Belgium.

PMID: 31051386
DOI: 10.1016/j.scitotenv.2019.04.344

Abstract

Freeze-thaw cycles are important in the weathering behaviour of natural building stones in humid, cold to temperate climates. It is expected that the elevated air temperatures in urban environments, the so-called urban heat island (UHI), will have an impact on freeze-thaw weathering. In this study, the impact of the urban heat island on the potential freeze-thaw risk is assessed by parameterization of climatic data of 1 year (07/2016-06/2017) from the MOCCA (Monitoring the City's Climate and Atmosphere) project, which studies the urban heat island in Ghent, Belgium. The dose-response of Savonnières, a French limestone often used as building stone, is investigated in laboratory and by HAM simulations. Analysis of the MOCCA data demonstrates that the urban heat island phenomenon decreases the number and intensity of freeze-thaw cycles in an urban environment with 42% and 41% respectively for the studied year in Ghent. This decrease suggests a mitigation of frost risk in urban environments. Laboratory tests and computational simulations confirm that this leads indeed to a decreased freeze-thaw risk in urban landscapes compared to the surrounding rural environment.

Keywords: Heat air moisture (HAM) transport; Heritage; Ice crystallization; Urban climate; Zero curtain effect.