RECYCLED AGGREGATE CONCRETE AND METHOD FOR PRODUCING THE SAME

PROBLEM TO BE SOLVED: To provide recycled aggregate concrete which uses only recycled aggregate for whole aggregate, is easily produced and has improved strength and durability, and to provide a method for producing the same. SOLUTION: The recycled aggregate concrete is composed of cement, water and aggregate, wherein the whole amount of the aggregate is composed of the recycled aggregate. The blending ratio of water to cement is 25-35%, and the unit water amount is 145-155 kg/cm3. When an admixture is added to cement in an amount of 0.5-1.5% based on the amount of the cement and the resulting mixture is kneaded, a number of fine independent air bubbles are incorporated into concrete. Thereby, good slump performance can be kept. Since the transition zone of the recycled aggregate surface becomes dense by setting the ratio of water to cement to be ≤35% and setting the unit water amount to be ≤155 kg/cm3, the absorption of water onto the recycled aggregate is restricted. Consequently, the strength, freezing and thawing resistance, and drying shrinkage property of the concrete are improved, and strength and durability nearly equal to those of normal concrete can be secured although only the recycled aggregate is used as the whole aggregate. COPYRIGHT: (C)2010,JPO&INPIT