Recycled Aggregate Concrete Additive for Slump Retention

The patent introduces a special additive system as an intermediary between recycled aggregate and concrete mixture. The additive includes water control agent (5-15 parts) to manage water absorption, powder and cement regulator (5-15 parts) to control mud content effects, and strength enhancer (5-20 parts) to compensate for low crushing value. This intermediary system transforms the problematic recycled aggregate into a usable component while maintaining concrete quality standards.

The patent changes the chemical and physical parameters of the concrete mixture by adding specific compounds. The polycarboxylate superplasticizer (50-70 parts) modifies the water-cement ratio and flow characteristics, while the sustained-release agent (3-15 parts) controls the hydration process. These parameter changes enable the concrete to achieve required strength and durability despite using recycled aggregate with inherent defects.

The patent uses a relatively high dosage of polycarboxylate superplasticizer (50-70 parts, comprising 71.4-87.5% of the total additive weight) to ensure sufficient workability and slump retention for fully recycled aggregate concrete. This excessive action is compensated by the strength enhancer (5-20 parts) and sustained-release agent (3-15 parts) that prevent strength loss. The water control agent (5-15 parts) also helps manage the water absorption effects that would otherwise lead to over-plasticization.

The patent creates a composite additive system where polycarboxylate superplasticizer works synergistically with other components. The combination of superplasticizer, water control agent, powder and cement regulator, anti-sticking agent, super slump retaining agent, strength enhancer, and sustained-release agent forms a composite material that balances workability improvement with strength maintenance. Each component compensates for the potential negative effects of the others, achieving both good workability and adequate strength.