Feasibility Of Waste Concrete As Recycled Aggregates In Construction
Free (open access)
M N Abou-Zeid & S L McCabe
Recycled concrete has been gaining an increasing interest worldwide due to a multitude of environmental, economic and energy considerations. Among the key environmental concerns are depletion of natural sources of good quality aggregate materials, limited availability of landfills for the dumping of demolished construction waste and possible contamination of groundwater that results from washing out fresh concrete returned from job sites. When properly implemented, concrete incorporating recycled constituents can carry economic advantages and may result in considerable energy savings. Previous work has shown that recycled concrete can yield technical properties, which are comparable to concrete made with conventional materials. In fact, the authors -among other investigators- have strong indications that recycled concrete can yield superior quality in some aspects such as flexural strength, concrete durability and fire resistance. Yet, questions are still raised by contractors and applicators with respect to the acceptance and implementation of this composite as well as it overall feasibility in construction projects. This paper presents and overview of recycled concrete properties with alternatives for its preparation and handling. The data herein is acquired from selected international sources together with sample results from an ongoing experimental program jointly performed in the USA and Egypt. Parameters that govern the feasibility of using recycled concrete are highlighted and discussed. Obstacles encountered that can hinder its use are also stated with some suggested actions to be taken.