Joint sealing by injection for sealing construction joints in surface and subsurface constructions
Joint sealing is particularly important in concrete construction where construction joints are the order of the day. They occur when a structure is built of successive concrete sections. Construction joints in new buildings are sealed with suitable hydrophilic water bars, metal waterstops or joint sealing strips.
For the post-construction sealing of damaged construction joints we normally opt for the injection technique. Here, boreholes are drilled following a set pattern whereby the drilling axis should cross the joint directly in its middle. The holes are then equipped with injection lances through which the grouting material is injected under pressure into the joint.
During the injection process, the injection channel is filled first followed by the joint and later the cracks and gaps in the area closest to the joint. The grout then forces its way into large pores and cavities and later on during the injection process penetrates the capillary pores. Injection continues until counter pressure has built up in the structure and grout discharge is evident in the area of the joint or from the neighbouring injection lance.