How should excess water be removed from the surface of fresh concrete?

The recommended method for removing excess water from the surface of fresh concrete is to use a squeegee or vacuum before finishing. This approach is important because excess water can lead to several issues in the final concrete surface, such as improper finishing, reduced strength, and increased susceptibility to defects like scaling or cracking.

Using a squeegee helps to effectively remove standing water without disturbing the surface of the concrete. It prepares the surface for finishing operations, ensuring that finishing tools such as trowels or floats can be used on a surface that is appropriately moist rather than waterlogged. A vacuum can also be employed to suction away excess water, which is a particularly effective method for ensuring a clean, dry surface ready for the next steps in the finishing process.

The other methods, while potentially applicable in some situations, do not adequately address the immediate need to remove excess water from the concrete surface. Allowing water to evaporate naturally can lead to inconsistent surface conditions and is not reliable in maintaining the desired moisture content for proper finishing. Covering with a tarp may inadvertently trap moisture, leading to issues with curing or surface defects. Using a broom to sweep water away is not effective, as it can disturb the freshly placed concrete and create inconsistent surface conditions.