Properties of hybrid geopolymer concrete prepared using rice husk ash, fly ash and GGBS with coconut fiber

Abstract

In this study, geopolymer concrete was developed using three by-product components i.e., rice husk ash (RHA), fly ash (FA) and ground granulated blast furnace slag (GGBFS) along with coconut fibres to promote sustainable development. The studies were carried out for the various mixes. RHA, FA and GGBFS were used as source materials in the percentages of 30, 30 and 40 respectively for M30 concrete. Alkali activator used in the analyses was the blend of NaOH of 16 M concentration and Na2SiO3. The ratio of 0.5 was maintained for alkaline activator to the source material. The coconut fibres were used in various percentages as 0 in control mix and 0.1, 0.2, 0.3, 0.4, 0.5, and 0.6% (by weight) of source material in hybrid specimens. A total of 168 specimens were cast and cured under sunlight for 48 h, following air curing for 48 h and then cured under normal supply water. The test outcomes indicated that the compressive strength rise significantly by 5.13% and 5.6% after seven and twenty-eight days respectively with coconut fibre content 0.2% of binder material and at the percentage of 0.4, the strength showed a decline of 0.42% and 0.7% for seven and twenty-eight days, respectively. Split tensile and flexural strength increased when the amount of coconut fibre used was 0.2% after that, a reduction was observed.