Hybridisation effect of steel-polypropylene fibres in high volume fly ash concrete

The paper presents result of an investigation conducted to investigate the footprints of fibre's hybridisation on workability, compressive strength, flexural strength and flexural toughness of High Volume Fly Ash Concrete (HVFAC). Different proportions of Polypropylene (PP) and Steel (S)fibres i.e. 100%PP-0%S, 75%PP-25%S%, 50%PP-50%S, 25%PP-75%S and 0%PP-100%S, were incorporated at the total fibre volume fraction of 1.0%. Further, three different methods JCI, ASTM C 1018 and ASTM C 1609 were used for comparative evaluation of various parameters such as toughness, residual strength etc. It was observed that the concrete mixes with higher percentage of PP fibres resulted in lower workability as compared to mixes made with higher percentage of S fibres. Moreover, the concrete mix with 25%PP-75%S fibre combination showed the best results among all concrete mixes and is considered to be the most appropriate for hybridization in HVFAC. Highlights · Effect of hybridization of steel and polypropylene fibres at different percent combination on workability, compressive strength and flexural strength of HVFAC has been investigated. · Flexural toughness of HVFAC incorporated with different percent combination of steel and polypropylene fibres via enumerating various parameters like toughness, residual strength, first and ultimate crack strength, deflection etc. have been determined. · Comparison between different methods i.e. JCI, ASTM C 1018 and ASTM C 1609 has been highlighted. · The mix with 25%PP-75%S (M5) fibre combination showed the best results among all other concrete mixes and is considered to be the most auspicious hybrid fibre combination for enhancing the above given properties.