Effect of Polypropylene Fibers on Thermal and Some Mechanical Properties of No-fines Concrete


This research aims to find the optimum percentage of polypropylene fibers that can be added to no-fines concrete. The fibers added to the (1:5, 1:6, and 1:7 mix proportions) concrete with volumetric percentages of (0.1, 0.2, 0.3, 0.4, and 0.5%), together with suitable amounts of superplasticizer to keep the flow percentage at (65-75%) using constant w/c ratio of 0.4. The results indicated that the optimum volumetric percentage of the added polypropylene fibers is 0.3% which needs small amount of superplasticizer of 0.5% by cement weight, to keep its flow equivalent to the reference mix. This percentage of fibers cause an increase in compressive strength, splitting tensile strength, and modulus of rupture of 22.5, 56.1, and 67.8% respectively when using 1:5 and 1:6 of concrete mixture. But this percentage decrease when using concrete mix proportion of 1:7 to be 8.8, 23.8, and 24% respectively. Also, results indicated that concrete density and thermal conductivity didn’t affect significantly by fibers addition.