How should you measure and control concrete temperature on site and why matters to finishing?

• A. Use a calibrated thermometer; maintain recommended temperature ranges to control set time, workability, and finish quality; extreme temperatures accelerate or retard finishing
• B. Use a rough estimate by touch; temperature has no effect on finishing
• C. Temperature is only important for color
• D. Temperature determines only the water-to-cow ratio

Answer: (A)

Controlling concrete temperature is crucial because temperature directly drives the hydration process, which in turn affects set time, workability, and the quality of the final finish. You should measure temperature with a calibrated thermometer or a proper temperature probe, inserting it into the fresh concrete at a representative depth (often near the core) to get an accurate reading of the mix temperature. Track and record these readings from placement through early curing so you can compare against the project’s specified temperature range.

Keep the concrete within the recommended temperature window because extremes change how the concrete behaves. If it’s too hot, hydration speeds up, reducing workability and making finishing difficult and prone to early surface defects. If it’s too cold, hydration slows, delaying set and complicating finishing operations, but it can also improve workability if the mix becomes too stiff. To achieve and maintain the right temperature, you can use cool water or ice to lower the mix temperature, shade or misting in hot conditions, heated aggregate or insulated covers in cold conditions, and other approved temperature-control measures per the project specs.

In short, accurate measurement with a calibrated tool and staying within the target temperature range ensure the set time, workability, and surface finish stay within expectations, avoiding finishing problems caused by temperature extremes.