How do you minimize plastic shrinkage cracks in hot, windy conditions?

• A. Increase cement content.
• B. Use curing, moisture retention, and moisture control during placement.
• C. Skip curing to save time.
• D. Place in cold weather only.

Answer: (B)

In hot, windy conditions, the surface of fresh concrete loses water quickly, creating plastic shrinkage cracks as the interior hasn’t finished hydrated yet. The best approach to minimize these cracks is to use curing, moisture retention, and moisture control during placement. Proper curing keeps the surface moist, slowing evaporation and allowing ongoing hydration, which reduces surface tensile stresses. Moisture retention methods, like damp coverings or curing compounds, help maintain surface moisture after placement. Controlling moisture during placement—through means such as windbreaks, fogging, or covering the slab—limits evaporation when it’s most critical. Increasing cement content can actually raise heat and shrinkage, skipping curing removes the essential moisture for hydration, and placing only in cold weather doesn’t address the hot, windy scenario.