Study of Influence of RC Aggregate on Bond Behaviour&Chloride Conductivity

Aggregates are inert granular materials such as sand, gravel, or crushed stone that, along with water and Portland cement, are an essential ingredient in concrete. Natural sand, graveland crushed stone exist most abundantly in the natural world, thus these materials are most frequentlyused for infrastructure development. Although the aggregate situation varies by country and region, thereplacement of natural aggregate with crushed stone aggregate has progressed in recent years due to environmental restrictions. It is believed that this has also led to changes in the quality of aggregate, which greatly affects the quality and durability of concrete. On the other hand, the waste generated from the demolition of old structure and construction activity is a matter of concern all over the world. Thus, recycling and reuse of these wastes may reduce the usage of natural resources and it can also serve towards the demand of environment. The present paper gives a brief status of recycled aggregate concrete made out of recycled aggregate, summarizes and critically analyses some of the most important research findings over the past few years regarding the material aspects. It also attempts to elucidate the approaches for the better performances, identifies the gaps in the existing knowledge and underlines the reasons why this promising technology has not become widely accepted by the construction industry. The practical problems with application of recycled aggregate in concrete are also discussed.