THIN OVERLAYS OF STEEL FIBER REINFORCED CONCRETE AND CONTINUOUSLY REINFORCED CONCRETE STATE OF THE ART IN BELGIUM

In Belgium, resurfacing of existing roads with cement concrete has been a common practice for over a decade, with approximately 500 km of roads overlaid with continuously reinforced concrete pavement (CRCP). This interest expanded to include thin resurfacings (<15 cm) of steel fibrous reinforced concrete (SFRC) and thin continuously reinforced concrete (TCRCP) due to the advantages offered by steel fibrous reinforced concrete in terms of lower fiber content and better incorporation possibilities. Experimental sections constructed since 1982, covering nearly 25 km of roads, have explored the use of SFRC and TCRCP overlays on both old concrete and bituminous pavements. The study reveals promising outcomes for thin overlays in SFRC, particularly when applied over bituminous underlayers, showcasing remarkable and durable bond strength. The best results were achieved with new leveling courses with an overall open structure. On old concrete pavements, achieving an adequate bond is crucial for success, necessitating intensive roughening of the existing surface. Grout application showed minimal improvement in bond strength. TCRCP overlays, particularly those with a thickness of 14 cm, demonstrated satisfactory performance with no significant issues. Utilizing welded-wire fabric for reinforcement can offer cost savings and facilitate construction under traffic conditions. This research, conducted with financial assistance from the IRSIA organization and supervised by a Working Party chaired by Prof. dr. ir. F. Van Cauwelaert, aims to establish practical guidelines for thin resurfacing and explores the relationship between empirical experience and thickness design computations. The study underscores the potential of thin concrete resurfacings in the rehabilitation of the Belgian road network, emphasizing careful consideration of bond strength and overlay thickness for successful implementation. (Abstract generated by AI tool ChatGPT 4)