What happens when concrete temperature is outside the recommended range?

• A. Extreme temperatures accelerate or retard finishing, affecting workability and finish quality
• B. Temperature has no effect on finishing
• C. Temperature only affects color
• D. Temperature only affects curing time but not finishing

Answer: (A)

Temperature controls how fast concrete hydrates, which directly affects how workable the mix is and how easily you can finish it. In hot conditions, the mix stiffens quickly and water can evaporate fast, giving you little time to strike off and smooth the surface. That often leads to a rough, uneven finish and sometimes surface cracking from plastic shrinkage. In cold conditions, hydration slows, delaying setting and finishing time; the surface can become dull or chalky if not finished or cured properly, and near-freezing temperatures raise the risk of freeze-related damage if moisture is trapped. So when concrete temperature is outside the recommended range, finishing is accelerated or retarded, and both workability and finish quality are affected.