At the other side of the chemical grouting spectrum are hydrophilic or “water loving” materials. Hydrophilic grouts thrive on water and seek it out within the crack and all the tributaries and fissures associated with it. This type of grout cures to a flexible foam or gel. During their curing process,hydrophilic grouts absorb and retain water molecules. This process allows them to expand into and replace the water that may be lurking in the finer cracks
and fissures that extend from the main crack being treated. This is the key attribute that makes hydrophilic grouts preferred over the hydrophobic type in situations where movement along the crack is expected. A tenacious mechanical bond is created within the dynamic crack due to the grout’s ability to lock itself into the crack. As the crack goes through expansion and contraction cycles, the hydrophilic grouts easily move with it.
Hydrophilic grouts need to constantly be in the presence of water. Long dry periods will cause the grout to dehydrate and shrink, creating the possibility of leakage through the treated area. Mining & tunneling projects are prime applications for the hydrophilic type of chemical grout. Regardless of the type of chemical grout used on the project, the application means and methods are relatively the same. There are numerous applications where either type of grout will perform perfectly. The key to chemical grouting is delivering the material to the point where water is invading the substrate and closing down that point of entry.