Waste Materials

Waste Materials

Waste Materials

Introduction

Construction output is increasing rapidly in most countries, resulting in a corresponding increase in the utilization of natural resources. Approximately 40 percent of the materials produced are utilized in building and construction work. Further, the construction industry consumes 25 percent of virgin wood, and 40 percent of the raw stone, gravel, and sand used globally each year. Materials account for the largest input into construction activities, in the range of 50-60 percent of the total cost.

In addition, a wide variety of materials is used in the construction industry. Unfortunately, this large portion of materials is not utilized efficiently by the industry. Evidence shows that approximately 40 percent of the waste generated globally originates from the construction and demolition of buildings (Rameezdeen 2004 pp.35-41)and this forms a major portion of the solid waste discarded in landfills around the world. For instance, in the USA it is approximately 29 percent (Ganesan 2000)and in Australia 44 percent of landfills by mass(Kwan 2003 pp.19-23).

Further, research indicates that 9 percent of the total purchased materials end up as waste (by weight) and 1-10 percent of every single material contributes to the solid waste stream of the site . Many researchers have shown that there is a positive correlation between waste prevention and environmental sustainability.

Construction and demolition waste have become a burden to clients, as they have to bear the costs of waste eventually. The cost of waste blunts the competitive edge of contractors, making their survival more difficult in a competitive environment. Companies that produce a higher level of waste are at a 10 percent disadvantage in tendering. Thus, Holm (1998)argues that construction waste can significantly affect the performance and productivity of an organisation.

Moreover, the generation of waste is a loss of profits for the contractors due to extra overhead costs, delays and extra work in cleaning, lower productivity, etc. Construction waste is also a cost to the environment that threatens its resilience. The unavailability of dumping sites to accommodate the higher volumes of debris from construction sites is becoming a serious problem, and a day may come when restrictions are imposed on construction waste disposal.

The above context illustrates the problems associated with construction waste. Improving the quality and efficiency of the construction industry is highlighted by Ganesan (2000), where one way of achieving this target is stated as the reduction of waste at all stages of the construction process. Further, the report Better Public Buildings identifies measuring efficiency and waste as one of the priority areas for the industry to improve its performance. Thus, it can be seen that construction waste management has become an important area to improve the performance of the industry in terms of economic, quality, and sustainability aspects.

Construction waste

Even though there is widespread recognition across the world of the importance of moving towards sustainability, the construction industry is “notorious for producing huge amounts of construction and demolition waste” (Bossink & Brouwers 1996 pp.55-60). Construction waste as the difference between the purchased materials and those ...