PRODUCTION METHOD OF READY MIXED CONCRETE USING WASTE CONCRETE INSTEAD OF SAND AND GRAVEL AS AGGREGATES AND READY MIXED CONCRETE COMPOSITION

摘要

PURPOSE: Provided is a production method of ready mixed concrete for road paving, parking lot paving or concrete structures by using waste concretes instead of sand and gravel as aggregates. CONSTITUTION: The ready mixed concrete for construction structures is produced by the following steps of: (S100) crushing waste concrete to an effective size and removing impurities from concrete; (S110) separating crushed concrete into aggregates(=20-27mm size) and powders(=4-7mm size) by screening; (S120) mixing concrete pieces and natural gravels, having the same size, in a weight ratio of 0.3-0.5 : 1 to get mixed aggregates; mixing concrete powders and natural sands in a weight ratio of 1 : 1 to get mixed powders; (S130) feeding mixed aggregates, mixed sands and cement into each hopper and (S140) transferring; (S150) mixing 36-45wt.% of transferred aggregates, 35-43wt.% of mixed powders, 11-17wt.% of cement, 0.08-0.1wt.% of admixture and 5-7wt.% of water.