Slab Jacking – Development of New Materials

In order to extend the lifetime of concrete roads for many years, it is very important to secure a proper maintenance. Loosely embedded slabs, for example, should be stabilized and, if necessary, jacked in an early stadium in order to prevent further damage of these and the bordering slabs. The amount of necessary severe repair work can be reduced by performing a thorough maintenance. This leads to a better conservation of value over several years, less repair costs and a reduction of traffic obstructions. During the last years new products for slab jacking with high strength for heavy traffic and long lifetime have been developed. These are in particular polyurethane and silicate resin. Polyurethane is most suitable for jacking slabs and silicate resin is applicable for stabilizing slabs by filling hollows between slabs and the base course. The new materials which are successfully applied in the German market and recorded in the German Standards (ZTV BEB) are hardening within 20 minutes or less, while the older system with cement bounded mortar had much longer hardening times. Therefore the traffic blocking can be removed just after finishing the works. Consequently maintenance works are accelerated and the traffic obstructions are reduced. This minimises the user delay costs and economical damage by preventing traffic jams.