Recycling of Demolished Concrete as Coarse Aggregate
Suvash Chandra Paul
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.