UTILIZING RECYCLED CONSTRUCTION AND DEMOLITION CONCRETE WASTE AS AGGREGATE FOR STRUCTURAL CONCRETE
Keywords:
Natural Aggregate (N.A.), Recycled Aggregate (R.A.), Water Absorption, Impact Value, Abrasion Value, Attrition ValueAbstract
This study investigates the use of recycled materials in concrete manufacturing
as a substitute for natural coarse aggregate to achieve the desired strength. It examines the
mechanical and physical properties governing the strength of recycled coarse aggregate
concrete compared to fresh concrete. The research employs various concrete specimens
made with recycled aggregate and evaluates them against conventional concrete. The study
also assesses the use of recycled aggregate in a consistent concrete mix of M20 with a fixed
water-cement ratio. Two different ages of recycled aggregate are considered, with a 30-year
age gap, and samples are compared to conventional cement. While few studies have
explored the use of fine aggregates in this context, none have discouraged their use in
construction. This project utilizes recycled aggregate in concrete and conducts laboratorybased
experiments by crushing concrete specimens (cubes and prisms). A total of 21 cubes
and 21 prisms are cast and tested for 28 days, with an additional 9 cubes and 9 prisms cast
using different proportions of recycled coarse aggregate (30%, 60%, and 100%) for one age
of recycled aggregate. Furthermore, 9 additional cubes and 9 prisms are cast using recycled
aggregate from another age, along with virgin coarse aggregate. The remaining 3 cubes and
3 prisms are made using conventional M20 mix concrete. The study aims to reduce
concrete waste, address ecological challenges, and mitigate the negative impact of natural
coarse aggregate extraction. It focuses on recycling construction waste from demolished
concrete structures to extract aggregate for use as a replacement. Given the challenges
faced by emerging nations and cities in managing construction waste, this research
investigates whether recycled aggregate from demolition debris can effectively substitute
natural coarse aggregate in concrete structures while maintaining the same strength. The
recycled material, obtained from various locations and ages, undergoes processing and
experimentation using a control mix of M20, replacing locally available concrete mixtures
at proportions of 30%, 60%, and 100%.
