Concrete, for a long time an object of criticism, is coming back into its own. The material is now better able to comply with environmental standards, support innovation and accommodate a wide variety of aesthetic designs. It is being extensively researched within the Group.
The Group's experts are devoting unremitting attention to concrete and coordinating work on it - supporting PhD theses, creating formulations and performing studies of its components. ""50% of our studies are devoted to concrete,"" says Sabine Darson-Balleur, who heads the Materials laboratory at Soletanche Bachy. ""Chemistry now makes it possible to improve the performance of the material while guaranteeing its application and durability. We are therefore able to formulate high-strength foundation concrete for complex structures, even when they are located in corrosive environments. This requires upstream work on materials all over the world as well as local standards and production methods, so that we can come up with the right solution."
All research is backed by tests carried out in the conditions in which the concrete will be used. ""We are carrying out full-scale tests at the Marolles site to understand the behaviour of ""improved-property"" concretes, such as those covered by the Befu (environmental concretes - formulation and use) project,"" says François Cussigh, a concrete expert at VINCI Construction France. ""Recently we also worked on eco-concrete (with a low-CO2 emission formulation) as part of the ANR project1. It is not enough to find the formulation. You have to demonstrate feasibility. Similarly, we have created software tools that demonstrate the material's durability."" These innovations must be regularly presented to the direct users. Lionel Linger, a concrete expert at VINCI Construction Grand Projets, confirms this. ""Concrete is a better insulating material, it is stronger. But we can only succeed in optimising its use if we analyse very carefully how its components - which we source locally - change over time. We must therefore study the impact of weather conditions, the quality of the soil and the time it takes to place the concrete in each element. Concrete is now a technically ""advanced"" material, and therefore tricky to manufacture and pour. Even the best concrete, if poorly vibrated2, will never fully meet the builder's expectations. We must therefore stay ahead of the curve and above all keep our teams constantly abreast of developments.