| Title |
An Experimental Study on the Workability and Engineering Properties of Recycled Aggregate Concrete Mixed Fly ash |
| Abstract |
For environmental and other reasons the number of readily accessible disposal sites around major cities in the world have decreased in recent years. At the same time critical shortages of good natural aggregate are developing in many urban areas, and distances between deposits of natural material and sites of new construction have grown higher, and transportation costs have become correspondingly higher.But recycling of waste concrete will contribute not only to the solution of a growing waste disposal problem, also help to conserve natural resources of aggregate and to secure future supply of reasonably priced aggregates for building construction purpose within large urban areas.But these recycled aggregates are more porous and less resistant to mechanical actions. In comparison with natural aggrete concrete, recycled aggregate concrete shows reductions in strength and other engineering properties. And it may also be less durable due to increase in porosity and permeability.Economical ways of improving the quality of recycled aggregate concrete are: (1)by reducing the water-ratio ;(2) by reducing the water content using a superplasticizer without affecting the workability ; (3)addition of pozzolan, sush as fly ash; and (4)blending of recycled aggregate with the natural aggregates. |