Vol.:(0123456789) 1 3 Clean Technologies and Environmental Policy https://doi.org/10.1007/s10098-019-01749-2 ORIGINAL PAPER Bacterium‑incorporated fy ash geopolymer: a high‑per formance, thermo‑stable cement alternative for future construction material Avishek Chatterjee 1  · Atreyee Sarkar 1  · Sudip Ghosh 1  · Saroj Mandal 2  · Brajadulal Chattopadhyay 1 Received: 28 May 2019 / Accepted: 7 August 2019 © Springer-Verlag GmbH Germany, part of Springer Nature 2019 Abstract Cement, the primary construction material, releases a substantial quantity of CO 2 (about 5–7% of total CO 2 emission) in the atmosphere during its production, thereby causing global warming. Fly ash is a coal combustion by-product that leads to many environmental problems like ground water contamination, spills, heavy metal contamination, etc. To overcome the serious ecological problems and health hazards of cement industries and thermal power plants, development of clean binding materials for construction purposes has become an interesting and new aspect of research to the scientifc communities. This study has been designed to develop and characterize 100% fy ash-based geopolymer by incorporating improved Bacillus subtilis cells which may be used for cement alternative in future. The designed geopolymer showed signifcantly increased compressive, fexural and tensile strengths, reduced water absorption capacity and increased sulphate and chloride resist- ance attributes. It also possesses enhanced durability with high-temperature tolerance (400 °C) compared to cementitious material. Microstructure analysis showed more compactness, reduced porosity and development of new phases inside the geopolymer matrix. The newly developed 100% fy ash-based geopolymer is an eco-efcient material which will reduce the pollution caused by fy ash and be used for sustainable construction purposes in the near future. Graphic abstract Keywords Compressive strength · Fly ash · Geopolymer · Microbes · Thermal stability Introduction Cement production releases a signifcant amount of solid waste and gaseous substances in the environment. It is estimated that about 5–7% of the total CO 2 anthropogenic Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10098-019-01749-2) contains supplementary material, which is available to authorized users. * Brajadulal Chattopadhyay bdc_physics@yahoo.co.in Extended author information available on the last page of the article