1.rainwater into the admixture tank, resulting in a decrease in concentration
When the concrete of the supply project was inspected by the testing platform before leaving the factory, it was found that the slump was too small.
Cause analysis,
Check that the inlet above the water reducer tank is not covered properly after it is opened by someone. It will rain heavily and the water that may wash the top of the tank will flow into the tank, resulting in a decrease in the concentration of the water reducer.Rainwater or water into the admixture tank, resulting in reduced concentration, resulting in low water reduction rate, concrete slump is small.
Prevention measures
After the feed supplier pumps the water reducer into the tank, it shall cover the top lid strictly in time, and the material personnel shall strengthen the inspection.
2. the admixture is of poor uniformity, resulting in local slow setting of concrete
One day, when pouring 14-storey wall column and 15-storey beam slab concrete on a construction site, the slump degree is too large, and the initial setting time exceeds 20 hours.
Cause analysis,
The failure of the agitator in the water reducing agent tank resulted in uneven density of the water reducing agent. The density of the water reducing agent in the lower part of the tank was too large, and the condensation time was too long. The concentration in the upper part was too small, and the condensation time was short.
preventive measure
The water reducing agent must be stirred regularly and evenly. The material personnel should strengthen inspection. If the agitator stops, it should be repaired immediately.
