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With rapid urbanization and along with the growing number of aging infrastructure, the re-development of housing and infrastructure as well as new construction to meet the increasing demand is generating large volume of construction and demolition (C&D) wastes. Construction and demolition waste is defined as the waste generated by all activities carried out during the construction, maintenance, demolition, and deconstruction of any type of building and civil work, or during natural disasters. Most of the time construction and demolition waste ends up in landfills disturbing environmental, economical and social life cycle.

At present, C&D waste poses a significant challenge due to its negative consequences, including environmental degradation and public health. Such a situation, with contribution to pollution, climate change, and resource depletion, requires an efficient framework to limit said consequences. Due to the high volume of C&D wastes that is produced every year, it is becoming vital that construction and demolition waste be managed in a sustainable manner. Recycling and reuse of such a large waste is need of an hour.

Recycling of C&D wastes refers to the practice of recovering, sorting, and processing of waste materials that are generated during the construction, demolition, or renovation of buildings, roads, and other structures. This process typically involves the recovery of wood, concrete, metals, masonry, insulation, plastics, and other materials that would otherwise be sent to landfills.

The major component of C&D waste comprises of cement concrete, bricks, cement plaster, rubble, stone e.g. marble, granite, sand stone etc. and steel from RCC, door/ window frames, roofing support, railings of staircase etc. While minor components include conduits of iron & plastic, GI pipes, iron, plastic, electrical fixtures of copper/ aluminum wiring, wooden batons, switches, wire insulation, panels i.e. wooden, laminated and others such as glazed tiles, glass panes etc.

Wood, metal and plastics are generally recycled easily however concrete, brick, rubble, stone, ceramic and mortar are generally available in mixed form and need processing to recover or produce Fine aggregates, Recycled Concrete Aggregates (RCA), Recycled Aggregates (RA) and Manufactured Soil. Recycling of C&D waste as secondary materials can supplement natural construction materials and would be a viable solution to eliminate environmental pollution, alleviate the problem of waste, and meet the demand for construction materials.

Fine and coarse aggregates are ready raw materials for RMC plants and construction sites. They are also good materials for road construction and rehabilitation. Recycled aggregates can be used in road construction, where it can be used as a partial or total replacement for natural gravel as a filler for road base or sub-base, and it can be used in pavement layers, whether rigid or flexible. It is also used to produce brick products such as solid bricks, porous bricks, permeable bricks, concrete kerbs and floor blocks. In addition, because of its high porosity, recycled aggregates is used to produce functional materials such as sound insulation concrete and pervious concrete.

The manufactured soil is quite suitable for landfill, landscaping as a substitute of excavated soil which leads to environment degrading low lying areas. The manufactured soil is also a good substitute for soil for construction of road and flyover embankments. It saves precious top soil. Porcelain can be crushed and resold to tile manufacturers, which can produce tiles made with up to 40% recycled materials. Wood can be chipped to make particle boards, pallets, or to create mulch for the protection and improvement of soil. The various downstream products which can be manufactured using recycled C&D waste are: bricks, blocks, tiles, hollow bricks, wall tiles, pavers, kerb stones, park benches, drain covers, planters, compound wall, fence post, tree guards, tree pit covers, manhole covers, underground cable covers, pre-cast boundary wall panels and poles, etc.

C&D Waste Recycling Plant Equipment

C&D waste recycling plant equipment are designed to segregate, sort, process, and recycle various types of C&D waste. These machines are designed to handle large volumes of waste, and they are available in different sizes and capacities to meet the specific needs of each recycling facility. Some of the common types of C&D waste recycling equipment include crushers, screens, shredders, grinders, and sorters.

Crushers are used to break down large pieces of C&D waste into smaller pieces that are easier to handle and process. Jaw crushers are commonly used to crush large pieces of concrete and brick, while impact crushers are used to crush materials such as asphalt and other non-abrasive rocks. Cone crushers are used to crush materials with high hardness such as granite.

Screens are used to segregate different sizes of materials from each other. They come in different configurations, including vibrating screens and rotating trommel screens. Vibrating screens are used to separate materials by size, while rotating trommel screens are used to separate materials by density. The screens are essential in the C&D waste recycling process since they help to remove unwanted materials that could contaminate the recycled products.

Shredders are used to break down materials such as wood and metal into smaller pieces for further processing. Single-shaft shredders are used to shred softer materials such as wood and plastics, while double-shaft shredders are used to shred tougher materials such as metal and concrete. Quad-shaft shredders are used for the most challenging shredding applications, such as processing mixed materials.

Grinders are used to grind materials such as asphalt and concrete into smaller pieces. They are designed to reduce the size of the materials, making them easier to handle and process. Grinders come in different sizes and types, including horizontal grinders and tub grinders. Horizontal grinders are used to grind larger materials, while tub grinders are used to grind smaller materials.

Sorters are used to separate different types of materials from each other. They come in different configurations, including manual sorters and automated sorters. Manual sorters are used to separate materials by hand, while automated sorters are used to sort materials using sensors and other automated systems. Sorters are essential in the C&D waste recycling process since they help to separate recyclable materials from non-recyclable ones.