Study On Properties Of Recycled Concrete

With the rapid development of the building industry, the wastes of building have been growing day by day, and most of them are waste concrete. Besides the charge for an abundance of waste disposal is very much, it also is harm to the environment and society. In addition, the large demand of concrete request the exploitation of natural resources—sand and stone, and so the natural resources has been on the exhausted edge for the unceasing exploitation. Moreover, besides the exploitation and transportation of natural sand and stone expands largely, it also destroys the environment badly. After waste concrete are crushed, removed impurities, classification, they can be used as recycled aggregates. The technology of using recycled aggregates to confect recycled concrete not only may resolve the environment pollution produced by the waste concrete, but also may save crude aggregates resource, and bring the prominent social benefit, economic benefit and environment benefit. It's a sustainable development road that can save resource and energy, alleviate the earth environment load and support the ecosystem balance.The research on the recycled concrete technology is inchoate in China. Most of the research are concentrated on the basic properties of recycled aggregate and recycled concrete, but the results don't agree with each other. No law which is essential and can direct the production can be draw from the existing research report.This paper summarizes that recycled concrete brings the influence to the environment and its domestic and international research status and development, and the recycled concrete technology is the need of social sustainable development. The paper designs a set of technology flow of producing recycled aggregates basing on the equipment of Southwest Jiaotong University building material laboratory and uses scrap concrete in Two belt highways of ChengDu to manufacture some recycled aggregates. and researches the basic properties of recycled aggregates such as apparent density ,absorption, crush index, compacted density, porosity, etc.The paper designs some teams of different mix proportion concrete according to the different replacement of the recycled aggregates and fly ash, and research their working properties and mechanical properties, and analyses influence factors of the working properties and the mechanical properties of the recycled concrete such as replacement rate of aggregates, the replacement amount of fly ash, sand ratio, etc.The paper studies on the Microstructure of the recycled concrete. And the morphology of concrete's hydrates, the defects in the Interfacial Transition Zone (ITZ) of the recycled concrete are tested by using scanning electro microscopy.Finally, the paper analyzes the feasibility of the application of the recycled concrete. It offers the advantageous support for the application of the recycled concrete.