Effect of different dosages of polypropylene fibers in thin whitetopping concrete pavements

An experimental laboratory study was undertaken to evaluate the engineering properties for four different concrete mixtures: a control mixture with no fibers and mixtures with polypropylene fibers using the following dosages: 3, 5, and 8 lb/yd ³ (1.78, 2.97, and 4.75 kg/m ³). Various samples were collected during construction and tested for compressive strength, flexural strength, and toughness using cylindrical, prismatic, and round panel specimens. Because the toughness results cannot be taken into account using common concrete pavement design methodologies, which is especially true for the round panel test, an analysis was performed that took into account the additional benefit of the polypropylene fibers using a residual strength approach. It was concluded that the effect of the addition of fibers was best captured using the round panel test. It was also concluded that the use of 5 lb/yd ³ (2.97 kg/m ³) fiber dosage had the best value-added benefit to the mixture.