Red Seal Concrete Finisher Practice Exam 2025 – Complete Preparation Guide

Shrinkage cracking in concrete primarily occurs due to the loss of moisture in the concrete as it cures. When concrete is poured, it contains a significant amount of water which is essential for the hydration process that develops strength and durability. As this moisture evaporates, the volume of the concrete reduces, leading to shrinkage. If the rate of moisture loss is too high—especially during the early stages of curing—cracks can form because the material loses its volume unevenly and can no longer support itself.

Inadequate measures to retain moisture, such as covering the concrete or misting it during curing, can exacerbate this issue, leading to the formation of shrinkage cracks. Understanding the relationship between moisture loss and the physical properties of concrete is crucial for preventing such problems in concrete finishing processes.