The construction industry is considered to be the main industrial polluter and exploits large quantity of our natural resources. Concrete is the most common building material in the globe. It is a manmade material which consists of aggregates bonded together with Portland cement and water. However, with the increase in demand of concrete, the demand of natural aggregates has been increased. As stated by Tsuno (2006), the global consumption demand for the natural aggregates ranges from 9 – 12 billion tons after the year 2010. With this demand, it leads to quarrying causing the depletion of our natural resources. The issue on the sustainability of our natural resources is posing some serious environmental threats and gaining worldwide concern. Hence it is necessary to find a suitable substitute which would help to control the rate of extraction of materials from quarries.
On the other hand, the global production of demolished concrete is estimated to range from 7.5 – 12.5 billion tons in the year 2017 (Mohammed, 2007). Demolition and construction waste are generated every year around the world due to the following reasons: (i) many old buildings, bridges, concrete pavements and other structures have overcome their age limit of use due to structural deterioration and need to be demolished (ii) structures are turned into debris resulting from natural disaster, and (iii) creation of building wastes resulting from manmade disaster. Continuously generated demolition and construction wastes are just being dumped in landfills. Disposal of these wastes is a very serious problem because it will require a large area of land and this tends to be difficult to find. So it is a must that the construction and demolition wastes will be accounted properly.
Many provinces here in the Philippines do not produce crushed stones but they do have a need for aggregates and these could be replaced with the recycled concrete (Ganiron Jr., 2015). Recycling demolished concrete as coarse aggregate in a new concrete is one of the best solutions to address the problems. This would help in reducing the detrimental environmental impacts and dealing with the construction wastes. Also, according to a report from the Iowa State University, the recycled concrete aggregate can reduce costs, and project delivery time (Garber, et al., 2011).