Well compacted, smooth subgrade is Part 1 in making successful slabs; Part 2 will cover formwork, joint details, vapor barriers and reinforcing.
The concrete slab can be thought of as the wearing cap for the building pad and base course. A well compacted and smooth subgrade is critical to a successful slab. Slab formwork, jointing details, vapor barriers and reinforcing must be installed correctly for the slab to function as designed.
Building Pad and the Base Course
Typically the building pad and base course will be designed based on a local soils report and installed by the site contractor. A third-party inspecting agency normally will monitorpecifications and confirm that moisture and density requirements are met. It is important that the concrete slab installer verify pad elevations and sub-base stability prior to starting the work.
Conducting a proof roll prior to installing the base course and slab placement is always a good idea and will quickly identify soft spots and potential rutting. Most proof rolling is done using a loaded dump truck or similar heavily loaded wheeled equipment.