When it comes to building a durable and sturdy cement concrete pavement slab, several crucial steps must be meticulously followed. In this comprehensive guide, we will walk you through each stage, breaking down the process into detailed actions that ensure a successful construction outcome.
The subgrade, consisting of natural soil, is compacted using rollers to achieve the required camber and gradient. Suitable templates are employed to check both cross and longitudinal profiles, ensuring a solid foundation.
Over the prepared subgrade, a base course or sub-base course may be added to provide a smooth, level surface and reduce the slab thickness. Various materials such as WBM surface, compact granular material layer, or stabilized soil base may be used depending on the soil’s bearing capacity.
Once the base is ready, formwork for the concrete slab is laid. These forms, made of steel or timber, should match the slab’s thickness, be securely fixed in position, and checked for proper alignment. Adequate oiling ensures easy removal, and thorough checks confirm correct line and grade.
After formwork installation, the base or subgrade is wet with water before placing the concrete mix. This prevents the surface from absorbing water from the mix, ensuring proper saturation.
Concrete ingredients are dry-mixed in a 1:2:4 ratio (cement:sand:coarse aggregates). The mix is placed in layers of 50 mm to 80 mm thickness, ensuring even distribution across the entire width of the formwork.
Vibrating hand screeds or tampers are used to compact the concrete mix. For larger projects, power-driven vibrators may be employed. Wooden hand floats are then used to achieve a uniform and even surface devoid of waves or corrugations.
Belting, carried out in a transverse direction, finishes the surface just before the concrete sets. Brooming follows immediately with a fiber broom brush to create a rough, non-slippery surface. Edging tools are then used to round transverse and longitudinal edges.
Initial curing begins after 12 hours by covering the surface with wet gunny bags for at least one day. Final curing involves removing the bags and covering the surface with a wet sandy layer for 14 days.
The pavement can be opened to traffic after 28 days of curing or earlier if the concrete has reached the required strength. During this period, brick edging is constructed to protect the slab, and earth may be spread on the berms to discourage traffic.
By following these construction steps diligently, you can ensure the successful creation of a durable cement concrete pavement slab ready for the demands of traffic and the test of time.
