Strengthening with concrete on the Nationale 6 in the Yonne County

For the "Nationale 6" thickening between Auxerre and Cravant, the concrete pavement solution, in competition with traditional techniques, is particularly interesting on the economic point of view and held the Head District Equipment attention in agreement with the French Road Management. The strenghening technique consisted in implementing by 4 m half width (making in the whole 8 m) a 22-crnaverage concrete thickness, in doing a roughening and stripping surface treatment and then in executing the longitudinal and transversal sa~ing for joints making. On these Il.S-km-long road works, about 25,000 m3 of portland cement concrete have been carried on between September 3rd and November 18th in a given time. For works, BEUGNET used a new compact slinform paver which has an exceptional mobility. This ne~ machine generation is indeed the new concrete pavement finisher for future. Besides the classical roughening, a 2-km-long test of a process has been impl~mented by BEUGNET and NORTH SCETAUROUTE when the A 26 motorway has been built' near St Quentin in agreement with the foreman (Yonne Head District Equipment). This stripping process, after adding a retarding admix on the surface, consists in showing, after water brooming, the 6/20 crushed stones which the concrete is made of. The roughness and the evenness shown after treatment are quite exceptional and users have the same guarantie~ as on very rough surface dressing pavements. Moreover, it is less expensive. In conclusion, these thickening works with their implemented equipment and innovating techniques proved that cement concrete pavement is now as easy to realize than a traditional one, still giving undeniable advantages for maintenance and durabi Ii ty, therefore a cos t saving.