Experimental Investigation on FACA and FACACRETE — An Innovative Building Material

Abstract

Recently, many studies are put forward by researchers to utilize waste materials like fly ash, GGBS, etc. in the construction industry due to the problems arise in the disposal of these materials. A novel study on incorporating the FACA (fly ash artificial coarse aggregate) in concrete is illustrated in this paper by comparing fly ash artificial coarse aggregate concrete (FACACRETE) with normal concrete. Different mixtures of geo-polymers were prepared using different molarities of NaOH solution and varying alkaline solution to fly ash ratio. These mixtures were cast to form a hard mass and cured. It is then pulverized in to fly ash artificial coarse aggregates (FACA). The properties of FACA were determined and are compared with conventional coarse aggregates. From the experiment, it is found that the FACA is a lightweight aggregate. It can be used for wearing as well as non - wearing surfaces as per IS: 383 - 2016. It is found that 8MA1 (8 Molar NaOH solution and 0.4 is the alkaline solution to fly ash ratio) is economical and can be used for further research as NaOH needed is less. This mix (8MA1) of FACA is used to prepare fly ash artificial coarse aggregate concrete (FACACRETE). The mechanical properties of both normal concrete and FACACRETE are compared and the results suggest that the compressive, splitting tensile, flexural strengths and the stress - strain relationship of FACACRETE is comparable with conventional concrete of same grade as per IS 456. The compressive toughness and compressive index of the FACACRETE is found to be more than the conventional concrete. The failure pattern of FACACRETE is associated with multiple cracking and that of normal concrete is localized failure. On considering the experimental investigations conducted here, it is found that the FACA can be used to replace conventional coarse aggregate in concrete. © 2019, Korean Society of Civil Engineers.