South Shore QC
Standards to be changed Even if the public authorities are constantly calling for the development of the circular economy, the use of materials from demolition-deconstruction is not yet easy. "When we are on a non-traditional constituent, questions related to the normative context arise" , launches Patrick Rougeau, materials and technology director at the Center for Studies and Research of the Concrete Industry.récupération de béton The concrete standard, mentioning the use of recycled aggregates from deconstruction for the manufacture of concrete, must evolve, believe the stakeholders. "Companies that build must still keep in mind the requirement for stability and mechanical resistance (durability, fire resistance, etc.). It's not a question of skipping stages, we want to build in complete safety", specifies Patrick Rougeau . Finally, the economic dimension remains in question. "We lack financial incentives. It would be good to make the use of recycled gravel compulsory, but today they are more expensive than virgin aggregates" , suggests Matthieu Dufeu, R engineer for the Metropolitan General Contractor Cooperative, a Norman construction company which also pre-fabricates concrete. The additional cost generated by the crushing of the concrete, in particular, penalizes the use of recycled materials. "Prefabrication can help with deconstruction. It consists of assembling concrete elements, which are very easy to cut to take them to the landfill, or reuse them as curbs" , adds Matthieu Dufeu. New technological developments to consider In this context, the collaborative research project Recybéton will come to an end next December. Managed by the Experimental Research Institute for Civil Engineering since its launch in 2012, it brings together 47 partners (public and private contractors, construction companies, design offices, etc.), for a budget of 4.7 million euros. A scientific publication as well as professional recommendations, in the form of a guide, are planned. "We confirmed what we already knew: we can recycle crushed concrete aggregates several times. When we crush, we produce a range of materials ranging from 0 to 30 mm. The sands therefore represent 50% of the production of crushed concrete. The development of the sector will not take place if we cannot recover this sandy fraction. I am convinced that there are still development deposits in crushing and sorting. In the Netherlands, there are up to five different crusher technologies" , Laurent Izoret is already advancing with L'Usine Nouvelle .