Cement was set in the piece shapes, solidified with submersion vibrators, then leveled and vibrated again with a double-beam vibrating screed. The vibrating screed was pulled over the concrete surface by two men. After screening, the concrete was instantly secured with a filter pad and a suction mat associated with a vacuum pump. Within seconds the vacuum made under the mat started to concrete the solid and cause water to be attracted through hoses to the suction pump.
Vacuum was connected for around 3 to 5 minutes for every inch of slab thickness. Ordinarily this brings down the water substance of the concrete by 20 to 25 percent, while the filter pad minimizes loss of cement fines with the water which is being gathered. Less t half of one percent of the cement is usually uprooted during vacuum dewatering. After a given area of floor was dewatered, the pad and mat were moved on to another newly placed section of the slab. The dewatered surfaces were sufficiently firm to be strolled on, and were instantly floated with a force trowel fitted with a planning disc to remove any high spots or abnormalities presented during the vacuum preparing.
Where skid-resistant surfaces are preferred, this finishes the floor- finishing operation, and the slab is prepared for curing around one-half to one hour after vacuum treatment. Where a smoother surface is determined, power troweling is done, for the most part 30 to 90 minute after the arranging operation.