What might indicate that temperatures are too high during concrete mixing?

The rapid setting of concrete during mixing can indeed indicate that temperatures are excessively high. When the temperature of the mixing water or the aggregate exceeds recommended limits, it can accelerate the hydration process of the cement. This causes the concrete to set faster than normal, which can lead to insufficient workability and difficulty in placing the concrete effectively.

Additionally, rapid setting increases the risk of cracking, as the concrete may not have time to properly cure and develop the necessary strength before it begins to harden. In high-temperature conditions, the concrete has a shorter window for placement and finishing, which can compromise the integrity of the final structure if not managed properly.

While thick consistency, a smooth finish upon setting, and low water content might relate to different aspects of concrete quality and mix design, they do not specifically indicate high temperatures during the mixing process. Therefore, the appearance of rapid setting is a significant indicator of potentially hazardous temperature conditions in concrete mixing.