The Theoretical And Experimental Research On The Development Of Building Matarials Of Wasted And Recycled Aggregates

Under the environment of reform and opening up and market economy, the economic construction of our country is developing quickly and steadily. The corresponding production and life demand for building is also growing, a large amount of new buildings take the place of many old buildings. The waste building materials especially concrete and garbage disposal are put in the landfill, it not only takes up a lot of space, but also pollutes the environment. The study shows that the waste concrete can be used to product recycled concrete aggregate to partly or totally replace the natural aggregate. It not only reduces the exploitation of natural resources, but also protects the environment from destroying.Mechanical properties of recycled concrete aggregate is worse than natural aggregate. On the basis of usage and performance of different type concrete, the research content mainly divided into three parts. Firstly, mixing waste cement mortar into foam concrete, and get the foam concrete block with lightweight and high strength. Secondly, adding the sugar water reducer and activated water to the recycled concrete, research the influence on the recycled concrete. Thirdly, research the influence of different factors such as the kinds and amounts of alkali and the water slag ratio on the strength of alkali inspire slag recycled concrete.The experimental results show that the factors such as cement, sand, plaster, hydrated lime, quicklime have great influence on the density and compressive strength. Sugar water reducer has delayed coagulation effect. When the age is larger than 0.3%C, the setting time is longer dramatically. Taking advantage of sugar water reducer and activated water, the compressive strength of recycled concrete is improved. The theoretical analysis and values are given, they are according with the experimental values. There are many different factors that affect the compressive strength, the sort and the content of alkali, the modulus of sodium silicate and the water slag ratio. Along with the content increase, the compressive strength increases firstly, then decreases. When the modulus of sodium silicate is 1.4, the content of Na2O is 8%, the maximum compressive strength is 57.3MPa when the curing period is 28 day. The micro-analysis of recycled concrete block is given through SEM, it is found that the quantity of porosity and fissure decreases, the strength of interface transition zone is improved.