Projekt

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Cement-free concrete: converting excavation material into sustainable concrete

Gesuchsteller/in Gnanli Landrou
Nummer 183409
Förderungsinstrument Bridge - Proof of Concept
Forschungseinrichtung Institut für Bau- und Infrastrukturmanagement ETHZ
Hochschule ETH Zürich - ETHZ
Hauptdisziplin Bauingenieurwesen
Beginn/Ende 01.12.2018 - 30.11.2019
Bewilligter Betrag 129'800.00
Alle Daten anzeigen

Alle Disziplinen (2)

Disziplin
Bauingenieurwesen
Materialwissenschaften

Keywords (5)

materiau d'excavation; economie circulaire; béton de terre; ecologie; resources

Lay Summary (Französisch)

Lead
Un procédé novateur pour transformer les matériaux d'excavation en béton écologique et moins cher.
Lay summary
L'industrie de la construction est confrontée à des défis majeurs, notamment la rareté des ressources, en particulier le sable et les émissions de CO2 dues à l'utilisation importante de ciment. De plus, il y a une demande croissante de logements abordables vue l'augmentation de la population globale. Entre-temps, des milliards de tonnes de matériaux d'excavation sont mis en décharge chaque année. Ces déchets sont actuellement inutilisés et occupent un grand volume d'espace.

Notre solution consiste à utiliser les terres d'excavation disponibles localement pour produire un béton de terre coulé. Parce que nous souhaitons que le procédé soit simple et compétitif par rapport au béton conventionnel, nous avons développé une technologie de béton sans ciment qui nous permet de mettre en forme la terre d'excavation à l'état frais en utilisant les mêmes infrastructures nécessaire que pour le béton puis d'accélérer le durcissement dans un temps assez court afin de retirer le coffrage après 24 heures.

Le béton d'Oxara présente les mêmes avantages de processus que le béton, mais il est 95 % plus écologique que le béton conventionnel et nettement moins cher. De plus, le béton Oxara a la performance mécanique pour supporter des maisons à 2 ou 3 étages. Une fois industrialisé, il constitue une solution durable au problème des logements abordables et contribuera à la réduction des émissions mondiales de CO2, des déchets de construction et de la consommation de sable.
Direktlink auf Lay Summary Letzte Aktualisierung: 16.11.2018

Lay Summary (Englisch)

Lead
A novel process to transform excavation material into sustainable concrete and facilitate access to affordable housings using locally available materials.
Lay summary

The construction industry is facing major challenges including scarcity of resources especially sand, CO2 emission due to large production of cement. Finally there is an increasing demand for affordable housing worldwide. Meanwhile, billions of tons of excavation materials are landfill per year. This waste material is currently un-used and occupy large volume of space.

Our solution consists of using the landfill waste (excavation materials) that is locally available to produce a poured earth concrete. Because we would like the process to be simple and competitive to concrete, we developed a cement-free concrete technology that allows us to cast the excavation materials in fresh state using concrete infrastructure and accelerate the hardening over time in order to remove the formwork after 24 hours

Now Oxara poured earth concrete has the processing advantages of concrete but it is 95% more eco-friendly  than concrete and significantly cheaper. In addition, Oxara concrete has the mechanical performance to support 2-3 storey houses. When industrialized, it constitutes a sustainable solution for the affordable housings problem and will contribute to the reduction of global CO2 emissions, construction waste and sand consumption.

Direktlink auf Lay Summary Letzte Aktualisierung: 16.11.2018

Verantw. Gesuchsteller/in und weitere Gesuchstellende

Mitarbeitende

Abstract

The construction industry has to address climate issues such as CO2 emissions due to cement production and resources depletion as billions of sand is used each year to produce concrete. In the meantime, construction activities generate billions of tons of excavation materials or earth which are currently wasted and landfilled. In Switzerland, 30 million tons of excavation material is landfilled each year in gravel pit and around 500 million tons is landfilled by the European construction sector. This is an important volume of construction resources unused and this leaves the construction loop open. Nowadays, the use of excavation material or earth has regained interest due to the environmental concern. Indeed, earth is one of the buildings material with the lowest environmental impact and it improves indoor air quality and wellbeing of residents. Despite these advantages, building with earth is time, labor and cost intensive. This hinder its uses as local resource to produce sustainable concrete. To stimulate sustainable activity and promote circular economy in the construction industry, we have developed at ETH Zürich an innovative process that upcycle and convert excavation material into sustainable cement-free concrete. The innovative process (DeCo process) consists of improving the fluidity of the materials by adding dispersants before casting, after which hardening is accelerated by adding a few percent of mineral additives. In this way, the formwork can be removed within 24 hours. This process, which is comparable to concrete casting, allows producing a low-cost and low CO2 earth concrete at a laboratory scale. The product: a cement free earth concrete is 2.5 times cheaper and 20 times more ecofriendly than current solutions. Moreover, it represents a good alternative to fired bricks and concrete block in low-rise buildings.In attempt to implement the technology and bring the product to the market, we will collaborate with industrial partners to build first industrial prototype but we need also to investigate the performance of the product depending on the variability of the excavation material. Therefore, the aim of the project is to demonstrate that the cement-free earth concrete products comply with the SIA and European construction norm. This step is crucial to convince construction stakeholders in using the products and it strengthens our business development strategy. To this end, we focus on the development and improvement of the cement-free concrete wall. We will achieve this by demonstrating the industrialization potential of the process. Then to ensure the trust from construction stakeholders in the new products, we will conduct certification test to show that the product complies the mechanical and environmental product declaration certification in large scale. Currently, the cement-free concrete has a compressive strength to support 3 to 4 story building, a strength comparable to fired brick and concrete block which are used as non-structural element. During the program, we will focus also on the improvement of the mechanical properties and the durability of the cement-free concrete products. We have presented the technology, prototypes to local recycling and construction companies who showed high interest. In fact, with our technology, they are able to sell construction waste at a high profit and turn the landfill activity into a more profitable business: a business we named Brown Gold. For this reason, we expect to sign a collaboration agreement for the first industrial, large scale prototype: PROOF of CONCEPT. We envision by the end of the Bridge project to introduce our large scale prototype to construction actors and turn project partners into paying customers.
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