Cement Grout

Cement grout is a fluid mixture of cement and water (often with sand, non-shrink/expanding admixture, or microfine cement) that is poured or pressure-injected to fill voids, cracks, ducts and gaps and to transfer load or seal against water. Common civil uses are: filling post-tensioning ducts to protect and bond tendons, bedding base plates and machine foundations (non-shrink grout), consolidating fissured rock/soil and curtain grouting for dams, filling honeycombed/repaired concrete, and anchoring rebar/bolts.

Grout proportions, water-cement ratio, fluidity (flow-cone time), bleed and strength are controlled to the application (e.g. PT-duct grout: high fluidity, low bleed, non-shrink, w/c ≈0.35-0.40). IS 456 covers grouting requirements for prestressed work; non-shrink grouts must show no settlement/shrinkage and develop the specified strength. Poor PT-duct grouting (voids, bleed lensing) is a notorious latent durability failure in bridges.