Spring 2007
Recycling of
Demolished Concrete as Coarse Aggregate
Suvash Chandra Paul
and
In
The % of wear value (abrasion value) of recycled aggregates is higher
than the normal aggregates due to the adhered mortar portion with the recycled
aggregates. The % of absorption of recycled aggregates is also higher compared
to the normal aggregates. For the same W/C, the strength and Young’s modulus of
recycled aggregate concrete are lower than the same made with normal aggregate
concrete. But if the W/C is reduced compared to the normal aggregate concrete,
recycled aggregate concrete gives higher strength and Young’s modulus compared
to the same of normal aggregate concrete made with a higher W/C. The
workability of recycled aggregate concrete is lower than the corresponding
normal aggregate concrete. It can be improved by coating recycled aggregate
with a cement paste before using as coarse aggregates for new concrete. Cement
paste coated recycled aggregates also give higher strength and Young’s modulus
compared to the same of non-coated recycled aggregates.