Vacuum Dewatering of Concrete

Vacuum dewatering is a process for large concrete floors in which, immediately after placing and screeding a workable (high-slump) mix, suction mats connected to a vacuum pump draw out a controlled amount of surplus mix water from the top 100-150 mm. Removing this water lowers the effective water-cement ratio of the surface zone after placement, so the floor can be placed workable yet finish dense, hard, abrasion-resistant and low-shrinkage — the basis of the proprietary 'Tremix' system.

Typically 15-25% of mix water is removed, giving roughly a 10-20% surface strength gain, reduced surface permeability and curling, earlier float/trowel finishing and earlier traffic. It is widely used for industrial floors, warehouses, parking decks and pavements where surface wear resistance and flatness matter. Process control (vacuum level, duration, immediate power-floating) is per IS 456 + system guidance.