1. The characteristics of the pumping agent are to improve the pumpability of concrete, that is, the concrete mixture must be able to pass through the delivery pipeline smoothly without clogging, segregation, and good visco-plasticity. Therefore, the performance requirements of the pumping agent have four characteristics: first, the slump after adding the pumping agent is more than 100mm higher than that of the benchmark concrete without mixing; second, the pressure bleeding rate ratio is not more than 90%; third, the slump is retained The value should still be greater than 150mm after 30 minutes, and should remain above 120mm after 60 minutes; fourth, the compressive strength at the 28d age should not be less than 90%.
2. Pumping agents with high-efficiency water-reducing admixture and retarding high-efficiency water-reducing admixture as main components are suitable for rich concrete.
The pumping agent with air-entraining water-reducing agent as the main component is suitable for medium concrete.
Pumping agents that add thickeners, water-retaining agents and air-entraining agents are suitable for lean concrete.
Pumping agents with specific special components are suitable for pumping concrete in specific situations. For example, pumping agents containing antifreeze components are suitable for pumping concrete construction in winter.
3. Pumping agents are mostly composed of water-reducing agents, retarders, air-entraining agents, thickeners, water-retaining agents, and specific components such as waterproof components, antifreeze components, and expansion components. It is compounded with components to adjust the compatibility of cement, so there are many varieties.
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