Performance Evaluation of Polypropylene Fiber Reinforced Concrete for Highway Pavements using GGBS as Cement Replacement

Abstract

Polypropylene fibre reinforced concrete offers crack-control and post-cracking benefits, while ground granulated blast-furnace slag (GGBS) can reduce Portland-cement demand and improve concrete durability. This experimental investigation evaluates M40 concrete for highway-pavement applications using five paired polypropylene-fibre/GGBS combinations: 0%/0%, 1%/10%, 2%/20%, 3%/30%, and 4%/40%, expressed by weight of cement. The reference mix was designed using IS 10262:2009 with a water-cement ratio of 0.35. Cubes, cylinders, and prisms were cast and water-cured for 7 and 28 days. Fresh-concrete workability was evaluated by slump, and hardened performance was assessed through compressive, splitting tensile, and flexural strength tests. Slump decreased from 95 mm for the control mix to 77 mm at the highest combined dosage. All three strength measures increased up to Mix M-3 containing 2% polypropylene fibre and 20% GGBS, then decreased at higher dosages. At 28 days, M-3 achieved 47.19 N/mm² compressive strength, 3.64 N/mm² splitting tensile strength, and 6.17 N/mm² flexural strength, compared with 42.07, 3.35, and 5.05 N/mm² for the control. The findings identify M-3 as the optimum combination within the investigated series.