Comparative Analysis of Green Roof Substrates with Recycled Materials: A Three-Year Study

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F24%3A00376815" target="_blank" >RIV/68407700:21110/24:00376815 - isvavai.cz</a>

Alternative codes found

RIV/68407700:21720/24:00376815

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Comparative Analysis of Green Roof Substrates with Recycled Materials: A Three-Year Study

Original language description

The study aimed to test newly developed green roof substrates containing a significant amount of recycled materials under real conditions and compare them with a commercially available substrate. A two-layer extensive green roof of 7x5 m2 was constructed using three different substates. Two of them were based of recycled materials to reduce primary materials extraction and increase the utilization of recyclate. These two substrates contained the same amount of recycled demolition waste with major proportion of crushed brick (37.5% by volume), but differed in the amount of pyrolyzed sewage sludge biochar (9.5% by volume in one and none in the other). The commercial substrate consisted mainly of expanded shale, lava and pumice. To enhance the water retention layer, hydrophilic mineral wool was used as the bottom layer of the green roof system. Vegetation was established using sedum carpets. The experiment was established in 2020. Undisturbed substrate samples were taken in 2021, 2022, and 2023 to monitor changes in hydrophysical properties, such as retention curves, saturated hydraulic conductivity, and grain size. Vegetation development was visually monitored over time, while substrate temperature and humidity were continuously measured by autonomous sensors. The results showed that plants in the biochar amended substrate rooted faster and achieved higher cover. Plants in the biochar-containing plot remained lush green for a longer period, even during periods of lower rainfall or more extreme temperatures, while those in plot with commercial substrate or without biochar turned red in response to stress. Moreover, the biochar-amended substrate showed a greater number of emergent plants, primarily grasses which is attributed to the increased availability of nutrients from biochar. The surface temperature amplitudes were higher than those of the substrate and mineral wool temperatures, locally influenced by the plant biomass surrounding the sensors. The temperatures of the substrate and hydrophilic mineral wool were more stable. Differences in substrate temperatures were observed particularly between substrates containing recycled materials and the commercial substrate.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20101 - Civil engineering

Project

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Continuities

S - Specificky vyzkum na vysokych skolach

Publication year

2024

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů