Effect of Embossed Straight Plastic Fibres with Varying Aspect Ratios on Compressive and Flexural Behaviour of OPC 53 Grade Cement Based Geopolymer Concrete
DOI:
https://doi.org/10.7492/633a4n18Keywords:
Geopolymer concrete, polypropylene fibres, flexural toughness, compressive strength, fly ash, alkaline activator, aspect ratioAbstract
Conventional OPC-based concrete is a major contributor to global CO₂ emissions, driving the need for sustainable binder alternatives such as geopolymer concrete
that utilise industrial by-products like fly ash. However, geopolymer concrete inherently exhibits brittle failure behaviour, and the role of embossed straight
polypropylene fibres, particularly the effect of varying aspect ratios on its mechanical performance remains insufficiently studied under Indian Standards.. This
experiment examines the influence of embossed straight plastic fibres (diameter 0.6 mm, lengths 30, 45, 60, 75 mm) added at 0%, 0.5%, 1.0%, 1.5% and 2.0% by
volume to a hybrid geopolymer concrete using OPC 53 grade cement (IS 12269) blended with Class F fly ash. The binder comprised 70% Class F fly ash and 30%
OPC 53, with a total binder content of 420 kg/m3. A 12 M sodium hydroxide solution and sodium silicate solution (Na2SiO3/NaOH = 2.5 by mass) were used as
the alkaline activator system, with an activator-to-binder ratio of 0.40. Compressive strength (100 mm cubes) and flexural behaviour (100×100×500 mm prisms,
two-point loading per IS 516) were evaluated at 28 days. Workability was assessed by slump test per IS 1199 (Part 2):2018. Results indicate 1.5% fibre volume
gives the best balance of retained compressive strength and substantially improved flexural toughness and residual load capacity, with flexural toughness increasing
up to 10 times compared to the control.
