Hydrophilic Grout And Hydrophobic Grout
The meaning of the word, hydrophilic in Latin (hydro=water and philic=affinity) is water affinitive. Hydrophilic chemical grout likes water and can produce either closed cell foam or a non-cellular gel when mixed with water. When activated, foams expand in volume between 5 and 8 times. Hydrophilic grouts chase and absorb the water in the cracks and in all of the fractures that branch off from the main crack. Moisture cured urethanes are used as hydrophilic grouts which are flexible and resilient after full cure and will allow movement to occur in the structure without damaging the seal or bond. Hydrophilic grouts are typically single component urethanes requiring small delivery systems for the injection process and have been successfully used in above and below-grade applications, but should preferably be used below grade as they will shrink in a dry environment. They are used for soil stabilization, sealing sewer joints, manholes and other underground applications.
The meaning of the word, hydrophobic, in Latin is (hydro=water and phobic=fear) water fearing. The hydrophobic grouts have an aggressive expansion rate and the reaction time.They immediately react with water to form carbon dioxide gas and turn into foam. Hydrophobic grouts repel water after activation. When injected into a wet cracks or joints, the hydrophobic grouts can trap water in the pores of the wet concrete.