Studies on eco-friendly concrete incorporating industrial waste as aggregates

Abstract

The present day research is focussed on development of alternative binder materials to Ordinary Portland Cement (OPC) due to huge emissions of green house gases associated with production of OPC. GGBFS-FA based geopolymer binders are an innovative alternative to OPC which can obtain high strengths apart from being eco-friendly; since its production does not involve high energy and also contributes to sustainability by using the industrial waste materials. Steel slag, an industrial by-product obtained from manufacture of steel can be identified as an alternative to natural aggregates for concrete production, since there is a possibility of acute shortage of natural aggregates in future. The present study is conducted to evaluate the performance of weathered steel slag coarse aggregates in GGBFS-FA based geopolymer concrete. GGBFS-FA geopolymer concrete with steel slag coarse aggregates are prepared by replacing natural granite aggregates at different replacement levels i.e. 0%, 25%, 50%, 75% and 100% (by volume) and various fresh and mechanical properties are studied. The flexural fatigue behaviour of GGBFS-FA geopolymer concrete with steel slag is also studied in detail. Efforts are also made to model the probabilistic distribution of fatigue data of GGBFS-FA geopolymer concrete at different stress levels using two parameters Weibull distribution. The results indicated that incorporation of steel slag in GGBFS-FA geopolymer concrete resulted in slight reduction in mechanical strength. The water absorption and volume of permeable voids displayed higher values with inclusion of steel slag. Reduction in number of cycles for fatigue failure was observed in geopolymer concrete mixes containing steel slag as compared to granite aggregates. Overall, the performance of steel slag was found to be satisfactory for structural and pavement application and steel slag can be recognised as new construction material. 2015