An Investigation of the use of Recycled concrete as aggregate in fresh concrete production

ABSTRACT

In recent years there has been an increase in the number of construction works and

concrete is the main construction material for most of the structures that are being

built. Nigeria is a developing Country with a large population and land area therefore

a consumer of concrete. This paper considers the option of recycling concrete in

order to meet the high concrete demand and effective management of construction

and demolition waste. The test focused on the use of recycled concrete as coarse

aggregate for concrete production. The coarse aggregate component of normal

concrete was replaced with 100% Recycled Coarse Aggregate (RCA) in a 1:2:4

cement, sand and aggregate mix proportion and 0.6 water/cement ratio and this

resulted to 17.13N/mm2 28 days cube strength as against the normal 24N/mm2 for

normal concrete. The experiment recommends that recycled coarse aggregate can

serve as a viable resource for manufacturing concrete, especially low strength

concrete. The economic benefit of RCA concrete includes efficient reuse of

recovered coarse aggregate from demolished and collapsed buildings and Recycling

of concrete debris can make a contribution to reduce the total environmental impact

of the building sector.

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