An overview on the influence of various factors on the properties of geopolymer concrete derived from industrial by-products

The enormous amount of industrial waste ash generated by power generation industry, timber manufacturing industry, iron and steel making industry, rice milling industry, mining industry etc have posed the aforementioned industry players a great challenge when it comes to the disposal of these ash materials due to the environmental, health, scarcity of lands and other issues. The best approach in overcoming the aforementioned waste management problems is to promote large volume recycling/reuse of these waste materials. In recent years, the rapid growth in research and development related to geopolymer binders has indeed indicated that the use of geopolymer offers the greatest potential in solving not only the waste management problems related to the aluminosilicate solid waste materials generated from various industries, but also the environmental degradation related to the use of OPC as primary binder material in the construction industry. Results of recent studies are indicative that geopolymer concrete fabricated using various industrial by-products exhibited similar or better mechanical, physical and durability properties as compared to OPC concrete. This paper presents a concise review of the current studies on the utilization of industrial by-products as the primary binder materials in the fabrication of geopolymer concrete. The effects of a number of major factors such as the use of chemical activator, post fabrication curing regime, particle size distribution of source materials, and aggressive environment exposure on the mechanical strength, physical properties, microstructures and durability properties of the geopolymer concrete are exhaustively deliberated. Besides, the current material design, fabrication procedures and post fabrication treatment procedures were rigorously reviewed to identify the limitations of the current geopolymer technology which impede its wide implementation in the construction industry. It has been identified that the high alkaline content in the material design and requirement for elevated temperature treatment of the contemporary geopolymeric binder are among the major technical challenges which resulted in the limited use of the material in the construction industry. Based upon that, numerous strategies were proposed to overcome the current limitations of the geopolymer technology towards promoting a large scale implementation of the technology in the production of construction materials. (C) 2015 Elsevier Ltd. All rights reserved.