2016. 02. 19..

Several years of fruitful cooperation between Colas Hungária’s Technology Directorate and the Paris campus of Colas SA paved the way for another study tour in France. This time, Hungarian Colas employees Sándor Szőke and Zoltán Domak had the chance to spend a couple of days at the Campus Scientifique et Technique (CST) in the town of Magny, just outside Paris.

During our stay in France, we encountered a lot of new solutions, such as the unique application of lean concrete pavement slabs. In the CST, the related process is different right from the first steps: as far as the mix design is concerned, they usually combine multiple fractions to prepare the suitable aggregate structure. Until the study tour, we were also unfamiliar with the use of
bitumen emulsion in lean concrete mixtures.

We also had the chance to observe the distinct installation procedure in photographs. The design process for bridge-construction concrete mixtures also entailed a couple of previously unseen techniques: for instance, our French colleagues apply metakaolin as an additive. The application of bitumen
emulsions and surface coatings also had some pieces of new information in store for us, because this technology is not generally accepted in Hungary yet.

A visit to a mixing plant was especially exciting for us, where we noticed interesting details, such as the bidirectional motion of the mixing skip above the product bin. In France, the recycling of milled-up asphalt is a general practice, usually in a 30% ratio. In some cases, the percentage of reclaimed-asphalt pavement materials reached 60% (even regarding mixtures used for motorway construction purposes) as part of successful routine works.