How does proper subgrade preparation affect the performance of concrete?

Proper subgrade preparation plays a crucial role in the performance of concrete by ensuring a stable base. A well-prepared subgrade provides uniform support for the concrete slab, which is essential for preventing issues that can arise from improper settling or shifting. When the subgrade is adequately compacted and graded, it distributes loads evenly and minimizes the risk of voids beneath the concrete, which can lead to uneven settling and cracking over time.

Cracks can develop if the subgrade is too soft, uneven, or compromised by organic materials that decompose. These issues can cause structural instability and affect the long-term durability of the concrete. By investing time and effort into proper subgrade preparation, the concrete achieves better load-bearing capacity and longevity, ultimately enhancing its performance and reducing the likelihood of costly repairs or replacements.

While other options mention aspects related to concrete setting time, curing, or surface finishing, they do not address the foundational importance of a solid and stable subgrade in maintaining the integrity of the concrete slab itself.