Cement Grouting for Cracks in Concrete and MasonryWide cracks, particularly in mass concrete abutments / piers and masonry substructures can be repaired by filling with portland cement grout. This method is effective in sealing the crack in concrete, but it will not structurally bond cracked sections.
Applications of Cement Grouting for Cracks
- When cracks are dormant
- Cracks are active but cause of cracking has been determined and remedial action has been taken.
- When honeycombing is present in concrete structures.
- When masonry is hollow.
- When deep leached mortar joints are present.
Materials Proportion and Pressure of GroutingOrdinary Portland cement to IS:269, sand and water are required. Admixtures to impart non-shrinkable properties and to improve flowability of grout may be added. The method of using admixture may be as per the manufacturer’s recommendations. The water-cement ratio (by weight) for the grout should be 0.4 to 0.5, the lower ratio being used when crack width exceeds 0.5mm. In atypical mix proportion for grout, 20 litres of water to be mixed with 50 kg of cement along with 225 gms of non shrink admixture, such as conbex 100 (of M/s Fosroc), should be used. The grouting pressure should be 2 to 4 kg/cm2.
Fig: Procedure for pressure grouting of concrete