Recyclage à froid du revêtement d’asphalte - USINE DE MÉLANGE
Nov 6, 2020
En Suède, environ 1 million de tonnes de vieux matériaux de chaussée sont recyclés chaque année.
Diverses techniques sont utilisées (froid, semi-chaud et chaud), dont le recyclage des installations à froid est devenu la méthode la plus courante pour les chaussées flexibles sur les routes à faible volume de trafic (ADTtotal <1500 vehicles/day). Cold recycling is an economical technique since the material does not need to be heated. The asphalt plants can easily be moved from place to place and are therefore suitable for small-scale production and for road construction in sparsely populated areas far from stationary plants. In cold recycling, up to 100% of the asphalt can be recovered, but for a good result it is important to crush and screen the old asphalt first. About 2.0–4.0% new bitumen emulsion is added, usually together with water and sometimes 10–20% virgin mineral aggregates. Various procedures have been developed to make the mix as homogeneous as possible and to ensure sufficiently good coverage with the emulsion. It is important that the quantities of new binder, water and mineral aggregate be determined through preliminary tests in the laboratory. A new test procedure for this type of mix has therefore been developed and is included in the new directives for cold recycling produced by the National Swedish Road Administration. The procedure comprises tests and specifications couvrant les domaines suivants :
â¢Échantillonnage et évaluation des anciens matériaux asphalte
â¢Composition du granulat (revêtement en asphalte récupéré, RAP)
• Directives pour choisir un nouveau liant et mélanger l’eau et les granulats minéraux
â¢Préparation et conditionnement des échantillons d’essai
• Conception du mélange et assurance qualité en testant les propriétés mécaniques et la durabilité du mélange recyclé.