Study On The Preparation Of Green High Performance Concrete With Recycled Aggregate

With the development of the social economy, urban construction has been updated and expanding. This brings a mass of construction waste and abandoned concrete blocks. In order to resolve the problem, reuse of construction waste is the best solution at present, which recycled aggregate concrete is the most reused way.According to conventional experimental methods, this paper systematically researched on physical and mechanical properties of two typical sources of recycled aggregate, and performance of preparation recycled aggregate concrete, such as:the method for measuring ratio of old mortar in recycled coarse aggregate, properties of mechanical with powder made of recycled fine aggregate used as mineral admixture mortar and concrete, the theory of strength of preparation concrete with recycled coarse aggregates, as well as the way of preparation of green high performance concrete with recycled aggregate.The thesis obtained some experimental results, such as:1. preparation of concrete with recycled aggregate from different sources is feasible; 2. new method for determination of old mortar ratio in recycled coarse aggregate is "the way of artificial selection-observation with the naked eye" and "the way of high temperature ball milling-artificial separation"; 3. strength of mortar with powder made of recycled fine aggregate used as mineral admixture is decreasing with increasing of dosge, while strength of recycled concrete is increasing at first and then continue to reduce with increasing of blending amounts; 4. all replacement of natural coarse aggregate concrete strength formula is f_cu0=-51.11W/C+82.775;5. the green and high performance of recycled aggregate concrete can be achieved by low water-cement ratio, high volume mineral admixtures and the right amount of superplasticizer; 6. resistance to chloride ion penetration of recycled aggregate concrete is worse than ordinary concrete, but it can be improved by replacing part of the cement with mineral admixtures; 7. C70 green high performance recycled aggregate concrete was prepared, and so on. It provided theoretical support for the same type of concrete preparation, and accumulated experimental experience for recycled aggregate research.