Evaluation on the usability of structure steel fiber-reinforced bituminous hot mixtures

• The L-LCSS and S-LCSS were used in the bituminous hot mixtures.
• Engineering properties of fiber-reinforced bituminous hot mixtures were investigated.
• Fiber rates and shapes have restricted the use of fiber.

The physical and mechanical properties of fiber-reinforced bituminous hot mixtures using low-carbon structure steel (LCSS) were investigated. Long (L-LCSS) and short (S-LCSS) fibers were used to prepare Marshall samples at ratios of 0.1% and 5% by the total weight of samples, respectively. The control Marshall specimen [N-LCSS (0%)] was prepared to evaluate waste fibers and its effect on bituminous hot mixture. Marshall Stability and flow tests were performed for different fiber ratios (0%, 0.1%, and 5%), and optimum bitumen ratios were determined. In addition, standard aggregate experiments were performed for the aggregate samples (similar aggregate samples were used for the three designs). A scanning electron microscope (LEO 1430 VP) was used to obtain surface images of the fibers. The test results indicated that L-LCSS can only be used in binder course. By contrast, S-LCSS can be used in wearing and binder course of flexible pavements as an additive because of its positive effect. The fiber ratio has restricted the use of fiber-reinforced bituminous hot mixture.