Contact grouting is the process of filling voids between two surfaces that are in contact with each other. There are a variety of applications for contact grouting in the installation and rehabilitation of pipes. The development of trenchless construction techniques like grouting contributes to the growth of the industry.
Contact grouting is used in the construction of bridges, buildings, dams, railways, roads and retaining walls, as well as in the pipelines and tunnels of trenchless construction. The term could almost be used interchangeably with grouting, except that contact grouting is used between two surfaces while grouting also includes the repair of cracks and leaks in pipes.
The method can seal any gaps between a concrete tunnel lining and surrounding rock. The result is the consolidation of these materials. Annular space grouting may be considered a form of contact routing.