Pressure injection is a method of strenghtening and waterproofing of building structures involving pumping an adequate injection material through injection holes. Properly performed injection results in effective saturation of a treated element with liquid injection material, thus causing its stabilization, strenghtening and waterproofing. Not only injection holes, but also fine cracks, pores and fractures get filled. Commonly used injection materials: acrylic-based resins, polyurethane resins, epoxy resins, cementitious grouts, siloxane-based materials and alcali metal silicates. Procedure of pressure injection should be performed after detailed analysis of the problem and of the condition of the repaired structure, and executed in a way that does not impair the safety of the structure.
Pressure injection is a perfect solution in situations when traffic reorganization would be extensively costly, and access to the damaged structure is very difficult. It can be executed in stone, concrete and masonry structures and at the joints of structures with adjacent elements. For more details go to injections in construction industry or injections in geoengineering.