Floating and troweling concrete too early in the curing process can cause which of the following?

Floating and troweling concrete too early in the curing process can cause which of the following?

• A. Too much aggregate brought to the bottom
• B. Excessive water brought to the surface
• C. Too much aggregate brought to the surface
• D. Excessive water brought to the bottom

Answer: (B)

Finishing a concrete surface too soon interacts with bleed water. As concrete sets, some water separates and rises to the surface. If you float or trowel before this bleed water settles, the finishing tools push that water up and carry some cement paste with it, creating a thin, water-rich surface layer (laitance). That excessive water on the surface weakens the top layer and leads to problems like dusting and scaling after curing. The other effects described (like moving aggregates or water ending up at the bottom) aren’t caused by finishing too early, so the right consequence of premature finishing is the excessive surface water.

Finishing a concrete surface too soon interacts with bleed water. As concrete sets, some water separates and rises to the surface. If you float or trowel before this bleed water settles, the finishing tools push that water up and carry some cement paste with it, creating a thin, water-rich surface layer (laitance). That excessive water on the surface weakens the top layer and leads to problems like dusting and scaling after curing. The other effects described (like moving aggregates or water ending up at the bottom) aren’t caused by finishing too early, so the right consequence of premature finishing is the excessive surface water.