Urbanization is creating enormous pressure for the effective utilization of the existing land with demolition of old structures for new and modern structures. The debris produced in demolition of these structures are in large amount and disposal of this waste in sustainable manner is the biggest challenge being faced today and should be considered as a resource. With the increasing waste production and public concerns regarding the environment, it is desirable to recycle these materials. If suitably processed in appropriate industrial plants, these materials can be profitably used in concrete. This chapter highlights the composition of construction and demolition waste, the necessity for its recycling, and possibilities that can be implemented for its resourceful use, further focusing on current trends in this field by elaborating various ways to use these waste from laboratory research scale to commercially available technologies around the globe. The chapter concludes with future research directions and guidelines for sustainable use of these wastes.
TopIntroduction
Construction and Demolition (C & D) waste comprises of a noteworthy part of aggregate solid waste production on the planet. C&D waste is produced at a point when any construction/demolition action happens, for example, building, streets, flyover, metro, rebuilding and so forth these wastes are substantial, possessing high density, and possess extensive and humongous storage space either on communal waste bins or on the roads. It isn't surprising to see tremendous heaps of such waste, which is substantial also, stacked on streets particularly in vast projects, bringing about traffic blockage and interruption. It compromises of 10-20% of the metropolitan solid waste (barring vast construction ventures). Consequently, proper management of such wastes is required.
With a tremendous increment in the number of disposable materials on one hand and a with lack of dumping sites on the other, the waste disposal issues are quite serious and at certain times, at the quite alarming rate.
Protection of the earth and preservation of the quickly decreasing natural resources ought to be the core of sustainable development. Persistent industrial improvement postures difficult issues of construction and demolition waste disposal (Timothy, 1998).
Though then again, there is basic lack of natural aggregate for generation of new concrete, on the another, the huge volumes of demolished concrete produced from crumbled and outdated structures make serious natural and ecological problems (Schachermayer, 2000). Reusing of total materials from construction and demolition waste may lessen the request – supply gap in both these segment.
Cement and brick waste can be reused by sorting, crushing and sieving into the recycled total. This recycle total can be utilized to make concrete for street construction and building material.
As per an examination commissioned by Technology Information Forecasting and Assessment Council (TIFAC), New Delhi, 70% of the construction business doesn't know about reusing and recycling strategies. The examination prescribes establishments and creation of quality benchmarks of recycled total materials and recycled total concrete. This would help in setting up a target product quality for the maker and guarantee the client of a minimum quality necessity, consequently reassuring him to utilize it.
The prospering population is making pressure for better use of land in existing urban communities. To provide the need for lodging and commercial prerequisite new construction is being finished by annihilating the old structures and construction on the empty land. The change in economic conditions in the developing nations has caused the large-scale development in the construction industry. This construction activity is creating an enormous volume of Construction and Demolition (C&D) Waste. Consistently around 3000 MMT (Million Metric tons) of waste is being created in European Union, out of which 30% of aggregate waste i.e. around 900 MMT is created by construction industry alone as C&D waste (Bravo, De Brito, Pontes, & Evangelista, 2015; Torgal, 2013). In the United States evaluate the formation of C&D waste is accounted for around 140 MMT every year (Torgal, 2013). In developing nations like India and China, there is a significant ascent in this C&D waste as detailed around 14 MMT is produced in Shanghai, China alone in 2012 (Ding & Xiao, 2014) Out of the aggregate waste around 80% comprises of bricks, blocks and concretes.
The illegal dumping and unarranged disposal of this C&D waste are causing the extreme biological and environmental concerns. Henceforth, the reuse and reusing of C&D waste is quite essential. Its planned utilization will not just decrease the misuse of virgin raw material yet additionally takes care of the issue of waste disposal. It additionally leads to greater accessibility of land by preventing dumping sites. Environmental effects, for example, deforestation, illicit mining of river beds for air and water contamination, utilization of fossil fuels and petroleum for transportation, topsoil loss and so forth is likewise diminished.