Article
PREPARATION OF BITUMINOUS CONCRETE MIXES BY USING CONSTRUCTION AND DEMOLISHED CONCRETE
The construction industry is one of the largest consumers of natural resources, especially natural aggregates, for the production of concrete and bituminous mixes. At the same time, it is also one of the largest producers of waste, generating millions of tons of construction and demolition (C&D) debris each year. Traditionally, these wastes have been disposed of in landfills or used in low-grade applications, thereby exerting additional pressure on natural aggregate sources and contributing to environmental degradation. To address these challenges, the recycling of construction and demolished concrete into aggregates for use in pavement construction offers an effective and sustainable solution. This research focuses on the preparation of bituminous concrete mixes using aggregates derived from demolished concrete. The study involves partial and complete replacement of natural aggregates with recycled concrete aggregates (RCA) obtained from C&D waste. Laboratory investigations such as Marshall Stability, flow value, bulk density, air voids, voids in mineral aggregates (VMA), and voids filled with bitumen (VFB) are carried out to evaluate the performance of these mixes. The results are compared with conventional mixes to determine the suitability of RCA in flexible pavements. The findings demonstrate that recycled aggregates, despite having slightly higher porosity and absorption than natural aggregates, can be successfully incorporated into bituminous mixes. Their angular texture improves aggregate–binder bonding and interlocking, while adjustments in bitumen content compensate for higher absorption. The use of recycled aggregates not only ensures sustainable utilization of C&D waste but also conserves natural resources, reduces construction costs, minimizes environmental impact, and aligns with the principles of circular economy and green highway initiatives.
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