IIT Madras uses Solar Thermal Energy to Recycle Waste concrete

Researchers at the Indian Institute of Technology Madras have developed a treatment process using solar thermal energy to recycle construction and demolition debris. Waste concrete from demolition was heated using solar radiation to produce recycled concrete aggregate (RCA); it was of higher quality compared to that obtained from mechanical crushing, and met the requirements for typical structural applications.

the Indian Institute of Technology MadrasBuilding demolition and waste concrete


The demonstration was done at the India One Solar Thermal Power Plant located in Shantivan - headquarters of the Brahma Kumaris organization in Rajasthan. The plant has 770 solar concentrators to produce electricity using steam generated at high pressure. The plant has been operational since 2017 and provides power to a community of about 25,000 people at a reasonable cost and has low maintenance. Two of the concentrators were used in the full-scale trials for treating the waste concrete.

By using concentrated solar energy for heating, the thermo-mechanical beneficiation of the concrete waste results in high-quality recyclable materials, which can substitute stone (blue metal) aggregates and sand in concrete. In this pioneering study, concrete from a demolition site was heated using solar radiation concentrated through large reflectors and cast iron receivers to more than 550°C, and subsequently scrubbed mechanically to yield coarse and fine RCA, with properties similar to those of pristine aggregates.

The findings of this trial were published in the reputed and peer-reviewed journal ‘Materials and Structures’ (https://doi.org/10.1617/s11527-022-02065-w) which was co-authored by Rohit Prajapati, Surender Singh, BK Jayasimha Rathod, and Prof. Ravindra Gettu.

the Indian Institute of Technology MadrasIITM team with Brahmakumaris staff at India One Solar Plant, Shantivan, Rajasthan


Elaborating on this study, Prof. Ravindra Gettu, VS Raju Chair Professor, Department of Civil Engineering, IIT Madras, said, “The intention of the present study was to develop proof-of-concept that solar radiation could be used in the thermomechanical beneficiation of concrete waste to produce good quality recyclable material for new concrete. This study 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, resulting in a circular economy.”

The objectives addressed in this study can be divided into three parts:

  • Use of concentrated solar energy in the thermomechanical beneficiation of concrete waste
  • Production of high-quality RCA from the waste
  • Assessing the performance of RCA in concrete to establish the fact that waste can be recycled.

Conclusions from the study can be summarised as follows:

  • It was observed that the required temperature of about 500 °C could be achieved and maintained for a long duration with the reflector-receiver set-up used.
  • Properties of the aggregates produced were found to be comparable with those of RCA produced in an electric furnace, with the total yield of recycled products being 90% of the feed concrete.
  • Preliminary results on concrete made with the RCA indicate its suitability for typical concrete applications.
the Indian Institute of Technology MadrasProcess flow of waste concrete recycling using concentrated solar energy


Concrete is the most common construction material used universally with an annual production estimated to be 10–30 billion tons. The global consumption of construction aggregates, including that needed for making concrete, is projected to reach 63 billion tons in 2024, according to studies. Practically, all aggregate demand is currently met by extensive quarrying and mining, leading to the depletion of primary mineral resources. Moreover, there is a severe shortage of fine aggregate in many countries due to bans on the mining of river sand to avoid serious environmental damage.

On the other hand, construction activities generate considerable waste, estimated to be about 3 billion tons per annum. Some developed countries recycle up to 90% of the construction and demolition (C&D) waste, while others still resort to dumping of large quantities in landfills. A rational way to provide an alternative supply of aggregates is through recycling of C&D waste, which would curtail mining for aggregates and free up space used as landfills.

the Indian Institute of Technology MadrasIITM team monitoring rise in temperature during experiment


Summary

  • The study attempts to mitigate the limitations of conventional thermomechanical techniques with regard to harmful emissions through utilization of concentrated solar energy.
  • The methodology was demonstrated at the India One Solar Thermal Power plant in Rajasthan and is expected to save 250 kWh of electricity per ton of concrete waste.
  • Heating is part of the treatment done on the waste to extract components that can be reused in new concrete.
  • Treatment can be deployed in large-scale construction projects and for demolition waste processing plants to make the construction industry more sustainable.
NBM&CW February 2023

No comments yet, Be the first one to comment on this.

×

Terms & Condition

By checking this, you agree with the following:
  1. To accept full responsibility for the comment that you submit.
  2. To use this function only for lawful purposes.
  3. Not to post defamatory, abusive, offensive, racist, sexist, threatening, vulgar, obscene, hateful or otherwise inappropriate comments, or to post comments which will constitute a criminal offense or give rise to civil liability.
  4. Not to post or make available any material which is protected by copyright, trade mark or other proprietary right without the express permission of the owner of the copyright, trade mark or any other proprietary right.
  5. To evaluate for yourself the accuracy of any opinion, advice or other content.
Thermax Acquires BuildTech to Expand its Footprint in Construction Chemicals

Thermax Acquires BuildTech to Expand its Footprint in Construction Chemicals

The recent acquisition of BuildTech by Thermax exemplifies a significant trend within the industry towards strategic expansion and enhanced capabilities in construction technologies.

Read more ...

Icrete By Amazecrete Enhances Strength & Durability of Concrete

Icrete By Amazecrete Enhances Strength & Durability of Concrete

Icrete has emerged as a new age material for Concrete Construction given its efficacy in increasing the strength and durability of concrete, bringing value additions and greater profitability to the users.

Read more ...

Cement Industry Targets Net Zero with 25% Emissions Reduction by 2030

Cement Industry Targets Net Zero with 25% Emissions Reduction by 2030

The Cement Industry is embarking on a Net Zero pathway, aiming for a 25% reduction in CO2 emissions by 2030 and a full decarbonization by 2050, driven by technological innovations, use of alternative raw materials, and circular economy

Read more ...

Determining Plastic Hinge Length in Precast Seismic Force-Resisting Systems

Determining Plastic Hinge Length in Precast Seismic Force-Resisting Systems

Plastic hinges form at the maximum moment region of reinforced concrete columns. A reasonable estimation of the plastic hinge length is key to successfully modeling the lateral load-drift response and conducting a proper seismic

Read more ...

Properties and Applications of Geopolymer Masonry Blocks

Properties and Applications of Geopolymer Masonry Blocks

Radhakrishna, Professor and Head, Department of Civil Engineering, RV College of Engineering, Affiliated to Visvesvaraya Technological University, Bengaluru. Block masonry is one of the oldest methods of construction. It is composed

Read more ...

Advancing LC3 Cement Technology for Sustainable Construction in India

Advancing LC3 Cement Technology for Sustainable Construction in India

Dr S B Hegde provides a deep, research-driven analysis of LC3 cement, emphasizing its chemistry, process innovations, global applicability, and success stories, and evaluates its technical advantages, performance, cost savings

Read more ...

Supplementary Cementitious Materials Improving Sustainability of Concrete

Supplementary Cementitious Materials Improving Sustainability of Concrete

Concrete is the second most consumed material after water in the world and cement is the key ingredient in making concrete. When a material becomes as integral to the structure as concrete, it is important to analyze its environmental impacts.

Read more ...

Alite & Belite in Portland Cement: A Key to Sustainability & Strength

Alite & Belite in Portland Cement: A Key to Sustainability & Strength

Dr. S B Hegde guides construction industry stakeholders on balancing cement’s early strength with long-term durability and sustainability and advocates optimized cement formulations and supplementary materials for more resilient infrastructure

Read more ...

Amazecrete: Offering Sustainable Concrete Solutions like ICRETE

Amazecrete: Offering Sustainable Concrete Solutions like ICRETE

V.R. Kowshika, Executive Director, Amazecrete, discusses the economic and environmental benefits of eco-friendly and sustainable products like ICRETE and the positive impact on the construction industry.

Read more ...

Admixture-Cement Compatibility For Self-Compacting Concrete

Admixture-Cement Compatibility For Self-Compacting Concrete

An admixture is now an essential component in any modern concrete formula and plays a significant role in sustainable development of concrete technology. Dr. Supradip Das, Consultant – Admixture, Waterproofing, Repair & Retrofitting

Read more ...

Amazecrete's Icrete: New Age Material for Concrete Construction

Amazecrete's Icrete: New Age Material for Concrete Construction

By maximizing the durability and use of supplementary cementitious materials, Icrete has emerged as a new age material for Concrete Construction V. R. Kowshika Executive Director Amazecrete

Read more ...

Nanospan’s Spanocrete® Reduces Cement & Curing Time in Fly Ash Bricks

Nanospan’s Spanocrete® Reduces Cement & Curing Time in Fly Ash Bricks

Hyderabad-based Ecotec Industries is a leading manufacturer of fly ash bricks and cement concrete blocks in South India under the trademark NUBRIK. Their products are known for their consistency and quality. Ecotec was earlier owned

Read more ...

Ready-Mix Concrete: Advancing Sustainable Construction

Ready-Mix Concrete: Advancing Sustainable Construction

A coordinated approach by the government, industry stakeholders, and regulatory bodies is needed to overcome challenges, implement necessary changes, and propel the RMC sector towards further growth such that RMC continues to play a vital

Read more ...

Advancements & Opportunities in Photocatalytic Concrete Technology

Advancements & Opportunities in Photocatalytic Concrete Technology

Research on photocatalytic concrete technology has spanned multiple decades and involved contributions from various countries worldwide. This review provides a concise overview of key findings and advancements in this field

Read more ...

Self-Compacting Concrete

Self-Compacting Concrete

Self-compacting concrete (SCC) is a special type of concrete which can be placed and consolidated under its own weight without any vibratory effort due to its excellent deformability, which, at the same time, is cohesive enough to be handled

Read more ...

Nanospan's Spanocrete® Additive for Waterproofing & Leak-Free Concrete

Nanospan's Spanocrete® Additive for Waterproofing & Leak-Free Concrete

Nanospan's Spanocrete Additive for Waterproofing & Leak-Free Concrete has proven its mettle in the first massive Lift Irrigation project taken up by the Government of Telangana to irrigate one million acres in the State.

Read more ...

Accelerated Building & Bridge Construction with UHPC

Accelerated Building & Bridge Construction with UHPC

UHPC, which stands for Ultra High-Performance Concrete, is a testament to the ever-evolving panorama of construction materials, promising unparalleled strength, durability, and versatility; in fact, the word concrete itself is a misnomer

Read more ...

Innovative Approaches Driving Sustainable Concrete Solutions

Innovative Approaches Driving Sustainable Concrete Solutions

This paper explores the evolving landscape of sustainable concrete construction, focusing on emerging trends, innovative technologies, and materials poised to reshape the industry. Highlighted areas include the potential of green concrete

Read more ...

GGBS: Partial Replacement Of Cement For Developing Low Carbon Concrete

GGBS: Partial Replacement Of Cement For Developing Low Carbon Concrete

Dr. L R Manjunatha, Vice President, and Ajay Mandhaniya, Concrete Technologist, JSW Cement Limited, present a Case Study on using GGBS as partial replacements of cement for developing Low Carbon Concretes (LCC) for a new Education University

Read more ...

To get latest updates on whatsapp, Save +91 93545 87773 and send us a 'Saved' message
Click Here to Subscribe to Our eNewsletter.