Exegy: a range of low-carbon concrete solutions

VINCI Construction is stepping up the pace of sustainable construction by promoting types of concrete with lower carbon emissions. With the launch of its new Exegy range of solutions, the company is promoting the use of low-carbon concretes on its worksites.

Main project's drivers for reducing the greenhouse gas (GHG) emissions

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Energy and resource efficiency

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Energy Decarbonisation

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Energy efficiency improvements

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Improving efficiency in non-energy resources

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Emission removal

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Financing low-carbon issuers or disinvestment from carbon assets

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Reduction of other greenhouse gases emission

Project objectives

To reduce the share of GHG emissions linked to concrete production by making low-carbon concrete solutions offering optimised technical, environmental and economic performance available for all VINCI Construction worksites.

As a European leader and global player in its sector, VINCI Construction’s aim is to leverage the power of Exegy in order to significantly develop the use of low-carbon concrete in all types of structures.

In keeping with its pledge to curb its greenhouse gas emissions by 40% by 2030, VINCI Construction is committed to using 90% low-carbon concrete in its projects by 2030, in order to bring down the overwhelming proportion of Scope 3 emissions represented by construction materials.

Cement alone is responsible for 85% of all greenhouse gas emissions from concrete, of which it is a traditional component. The main ingredient of cement, clinker, is obtained by heating a mixture of limestone and clay to a very high temperature (1,500°C). In addition to emissions generated by heating the kiln, during the firing process limestone releases the carbon contained in the material in gaseous form: this is known as decarbonation, which is responsible for around 60% of total emissions from cement.

By designing mixes containing little or no cement clinker and by substituting the latter with alternative cementitious materials, VINCI Construction intends to expand the use of low-carbon concrete. As part of a circular economy approach, VINCI Construction uses industrial by-products such as fly ash (a combustion by-product from thermal power plants) or blast-furnace slag (a by-product of the steel industry), combined with other mineral admixtures (limestone filler, pozzolana, metakaolins, etc.)

VINCI Construction thus offers a catalogue of low-carbon concrete solutions that meet Exegy standards, which categorise products according to their specific CO2 emission levels and technical characteristics, particularly as regards compressive strength.

Exegy solutions cover three types of concrete: low-carbon concrete (between 28 and 40% fewer GHG emissions), very low-carbon concrete (between 40 and 60% fewer GHG emissions) and ultra-low-carbon concrete (over 60% fewer GHG emissions).       
These solutions, which were designed and tested in VINCI Construction's materials laboratories and then approved and implemented on worksites, guarantee optimised technical, environmental and economic performance of the concrete. The expertise of VINCI Construction’s engineers and the know-how developed by worksite teams form the core of the EXEGY range of solutions.

 

More details on the complete project sheet to download

Emission scope(s)

on which the project has a significant impact

Scope 1

Direct emissions generated by the company's activity.

Scope 2

Indirect emissions associated with the company's electricity and heat consumption.

Scope 3

Emissions induced (upstream or downstream) by the company's activities, products and/or services in its value chain.

Emission Removal

Carbon sinks creation, (BECCS, CCU/S, …)

Avoided Emissions

Emissions avoided by the activities, products and/or services in charge of the project, or by the financing of emission reduction projects.

Scope 3 - Use of low-, very-low- and ultra-low-carbon concrete.

  • Quantification:

    600,000 tCO2eq/year by 2030 .

    of which 180,000 tCO2eq/year resulting from use of EXEGY Ultra-Low-Carbon concrete

VINCI Construction aims to use 15% Exegy ultra-low-carbon concrete on its sites by 2030, amounting to 1,400 cu. metres.

An emission factor of 100 kgCO2eq/cu. metre is assumed for ULC concrete.

Conventional concrete, which ULC concrete replaces, exhibits an emission factor of 230 kgCO2eq/cu. metre.

Hence the reduction of approximately 180,000 tCO2eq/year in 2030 (compared to 2020).

Key points

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Invested amount

500k€

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Starting date of the project

2017

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France and abroad

France et International

Project maturity level

Prototype laboratory test (TRL 7)

Real life testing (TRL 7-8)

Pre-commercial prototype (TRL 9)

Small-scale implementation

Medium to large scale implementationéchelle

Economic profitability of the project (ROI)

Short term (0-3 years)

Middle term (4-10 years)

Long term (> 10 years)

Illustrations of the project

The Exegy range of concrete contributes to the following SDGs:

  • SDG 6 – Clean water and sanitation: cement production consumes a large amount of water (up to 30% water in the paste when wet process is used)
  • SDG 12 – Responsible consumption and production: fostering circular economy solutions (blast furnace slag, fly ash)
  • SDG 13– Climate action: avoiding CO2 emissions from cement production as a means of fighting climate change

VINCI Construction has launched the Exegy approach to expand the use of low-carbon concrete.

Exegy solutions are distributed and sold via a network of partner concrete producers or, when possible, in mobile plants on worksites with the assistance of VINCI Construction engineers and experts. Exegy ultra-low-carbon concrete is expected to become a market success once it can be offered as a conventional engineering concrete, which will become possible once the ECOCEM Ultra® alternative binder is approved in the summer of 2021.

Exegy ultra-low-carbon concrete was developed by VINCI Construction and ECOCEM, working in partnership.

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Contact the company carrying the project :

Bruno PAUL-DAUPHIN exegy-solutions@vinci-construction.com

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