Recycling of Demolished Waste Concrete using Solar Energy

Problem Landscape

In India, 700 million tonnes of construction & demolition (C&D) waste is generated every year (GIZ report, 2016). This waste is typically considered of no value and mostly used in landfills as cover material, as filler material in low lying areas, and in non-structural applications. On the other hand, the demand for coarse aggregate and sand is estimated to be more than 2 billion tonnes and 1.4 billion tonnes respectively; by the year 2020 (Aggregate Business International, 2013). However, there is a huge scarcity of good quality aggregates and river sand all over the world.

The recycling of concrete waste can solve both the problem of managing concrete waste as well as provide an alternate to virgin aggregate and river sand. Our vision is to develop a novel sustainable technology for closed-loop recycling of concrete waste to produce good quality recycled products using solar energy.

In this project, a waste concrete recycling technology has been developed through optimized heat treatment. The properties of recycled products produced were found to be comparable to virgin materials available in the market. Optimization of heating process using concentrated solar power (CSP) technology is under development. Generally, concrete recycling plants possess high water foot print whereas our technology eliminates the use of water, making it more environment friendly.

The recycled products produced could be cheaper with the help of a closed loop supply chain and an efficient management plan. This project will also have a high social impact in terms of promotion of the non-renewable solar energy; reduction in C&D waste disposal and air pollution; saving spaces in landfill sites; prevention of contamination of municipal waste and ground water; keeping society and pubic area clean; eliminate illegal dumping; and less mining of natural raw materials.