RECYCLED AGGREGATES FOR CONCREATE USING REACTION OF RAPID CARBONATION

摘要

PURPOSE: Recycled aggregate for concrete using environment-friendly rapid carbonation reaction is provided to show similar dry shrinkage to that of common concrete made of natural aggregates. CONSTITUTION: Recycled aggregates for concrete have 3.1-8% of absorption rate. The recycled aggregates for concrete have absolute density of 2.2~2.49 g/cm^3. The recycled aggregates for concrete have pH of 11-12.5 and the size of 5-25mm. A method for producing high-density neutral recycled aggregates for concrete comprises the step of performing rapid carbonation reaction through which aggregate reacts to carbon dioxide in a closed chamber in order to neutralize Ca(OH)2 in mortar included in recycled aggregate more than 70%. Owing to the production method, the absorption rate of the produced recycled aggregate is dropped to 1.5-3.0%, and absolute density is increased to 2.5~4.0g/cm^3, and pH is decreased to 7.5-10.