India’s largest power producer and a public sector enterprise (PSE) under the Ministry of Power, NTPC Ltd has successfully developed geopolymer coarse aggregate from fly ash. The development will help in replacing natural aggregates reducing the impact on the environment.
NTPC’s research project on the production of geo-polymer coarse aggregate from fly ash has met the statutory parameters of Indian standards and the same was confirmed by the National Council for Cement and Building Materials (NCCBM).
NTPC has successfully developed geopolymer coarse aggregates as a replacement to natural aggregates. The technical parameters as per Indian standards for its suitability for use in concrete works were tested by NCCBM, Hyderabad, and the results were in the acceptable range.
The development is NTPC’s R&D achievement in expanding the horizon in ash utilisation, a company release claimed.
India’s demand for building aggregate touches close to 2000 million metric tonnes every year. The aggregate developed by NTPC from fly ash will help in meeting the demand to a great extent and will also reduce the adverse impact on the environment due to the quarrying of natural stone.
In India, every year, approximately 258 MMT of ash is produced by coal-fired thermal power plants. Out of this around 78 per cent of the ash gets utilised with the balance remaining in ash dykes. NTPC is exploring alternate ways to utilise the remaining ash, which includes the current research project to generate aggregates using more than 90 per cent ash.
The geopolymer aggregates can be extensively used in the construction industry. These aggregates are extremely eco-friendly and do not require any cement for application in concrete as the fly ash-based geopolymer mortar acts as the binding agent. The geopolymer aggregates will also help in reducing carbon emission and has great potential for the reduction of water consumption.