IIT Madras employs Solar Thermal Energy to recycle waste concrete

Subject: Environment

Section: Pollution

Concept:

The Indian Institute of Technology (IIT) Madras researchers have developed a treatment process involving solar thermal energy to recycle construction and demolition debris.
The demonstration was done at the ‘India One Solar Thermal Power Plant,’ located in ‘Shantivan,’ the headquarters of the Brahma Kumaris organization in Rajasthan.

Treatment Process

It has 770 solar concentrators to produce electricity using steam generated at high pressure.
The waste concrete from demolition was heated using solar radiation to produce recycled concrete aggregate (RCA) that was higher in quality when compared to those obtained from mechanical crushing.
The concrete made using this technology met the requirements for typical structural applications.
The plant has been operational since 2017 and provides power to a community of about 25,000 people at a reasonable cost and low maintenance.

Significance

Concrete is the most common material used in construction universally with an annual production estimated to be 10–30 billion tonnes.
The present study attempts to mitigate the limitations of conventional thermomechanical techniques with regard to harmful emissions through the utilization of concentrated solar energy.
It presents strong evidence for the use of concentrated solar energy for recycling waste concrete, with promise for large-scale waste concrete recycling.
This would reduce the energy footprint of Construction and Demolition waste processing significantly, and lead to savings in raw material and electricity, towards circular economy.