Utilization of coal- and biomass-fired ash in the production of self-consolidating concrete: a literature review

Both coal - and biomass-fired electric power plants have an enormous negative impact on the environments in which they are situated. However, there is potential to recycle waste such as coal ash and biomass ash for the production of high-performance concrete, i.e., self-consolidating concrete (SCC). This innovative high-performance concrete can flow and become compact under its own weight without segregation. Thus, the need for tamping and vibratory compaction is eliminated, which improves the production process and the performance of concrete structures. This article reviews SCC in terms of several aspects, including its history, the processes through which it is produced, and the mix designs used. The article also discusses the incorporation of four main by-products fly ash (FA), bottom ash (BA), rice husk ash (RHA), and sugarcane bagasse ash (SBA)-into the production of SCC. Due to the rapid expansion of industrial and agricultural operations, the disposal of by-products such as ash has become the subject of increasing environmental concern, and their use in the production of SCC constitutes a new material recycling and sustainability effort. The by-products act as filler materials and can participate in the pozzolanic reaction associated with cement hydration, often resulting in improved SCC performance. (C) 2015 Elsevier Ltd. All rights reserved.