What is bleed water in fresh concrete?

• A. Water that rises to the surface during early curing as the paste hydrates
• B. Water added for mixing
• C. Water that evaporates
• D. Water that leaks through joints

Answer: (A)

Bleed water is the water that rises to the surface during the early curing of fresh concrete as the cement paste hydrates and the aggregates settle. As cement hydrates, the paste becomes slightly more hydrated and fluid, and the heavier aggregates drop, pushing water upward through the mix. That upward movement brings some of the mix’s water to the surface, forming a visible layer. This isn’t water added for mixing, nor water that evaporates away or leaks through joints—the water comes from the batch itself and shows up at the surface as the concrete begins to set. Bleed water can carry fines to the surface, creating a thin laitance layer that can weaken the top if not cured or finished properly, so curing and surface finishing practices should account for it.