Anomalies and Countermeasures in the Use of Admixtures

Although concrete admixtures can effectively improve the performance of concrete, they may sometimes produce negative effects, especially when used improperly. It is important to pay attention to any anomalies that arise, identify their causes, and implement solutions. The following causes and solutions are provided for reference.

Cause: Poor compatibility of the admixture with cement or other raw materials; low dosage of the admixture; high cement or environmental temperatures leading to rapid hydration; improper concrete mix design.
Solution: Notify the admixture manufacturer to adjust compatibility with cement, and replace substandard raw materials; increase the dosage of the admixture and the amount of mineral admixtures; adjust the concrete mix design.。

Cause: Overuse of retarders or failure to adjust retarder dosage in response to sudden temperature drops; lack of attention to adjusting admixture dosage based on temperature and retarder conditions during production; changes in cement quality; quality issues with mineral admixtures; uneven mixing or insufficient mixing time leading to poor dispersion of the admixture.
Solution: Adjust the dosage of the admixture based on weather conditions; notify the supplier to reduce the dosage of the retarder or change the type of retarder; replace the cement or mineral admixtures; adjust the concrete mix design according to temperature changes during production.

Cause: Use of hard gypsum or industrial gypsum as a setting regulator with cement containing calcium lignosulfonate or calcium saccharate; presence of sodium carbonate in the early-strength agent; excessive dosage of triethanolamine; high temperature of cement; excessive dosage of early-strength agent.
Solution: Replace the cement or admixture; control the dosage of triethanolamine.

Cause: Improper concrete mix design with low sand content or insufficient cementitious material; excessive admixture dosage leading to high slump; improved compatibility between cement and admixture; excessive amounts of carboxylates, phosphates, or sugars in the retarder.
Solution: Adjust the concrete mix design, increase sand content or the amount of cementitious material; change the type of retarder and adjust the dosage of the admixture; incorporate thickeners or water-retaining agents such as air-entraining agents into the admixture.

Cause: Low sand content or insufficient cementitious material; low dosage of the admixture or inadequate water-reducing effect.
Solution: Adjust the concrete mix design to increase sand content or the amount of cementitious material; increase the dosage of the admixture.

Cause: Excessively low water-cement ratio, excessive dosage of water-reducing agent, or high cement content.
Solution: Adjust the concrete mix design to increase sand content or the amount of mineral admixtures; add an air-entraining agent; reduce the dosage of the admixture.

Cause: Excessive dosage of inorganic salt early-strength agents or antifreeze; inadequate early curing leading to rapid moisture evaporation.
Solution: Reduce the dosage of inorganic salt-containing admixtures, enhance curing, and avoid early moisture loss.