Recycling of Demolished Concrete

In Japan, it has been predicted that enormous quantities of demolished concrete will be produced in the future. Therefore, a great deal of research is being conducted to find ways to recycle this demolished concrete as concrete aggregate. However, because the characteristics of the original concrete are not well known in many cases, the results are also not clear. Moreover, the recycling of the cement in concrete is also necessary from the standpoint of resolving global environmental problems and achieving sustainable development. This paper describes the properties of the concrete made with recycled aggregates from the original concrete of known quality and the recycling of the cement in concrete as the approach that should be taken in the 21st Century.