Experimental Study on the Low-Cost Iron Wire Fiber Reinforced Asphalt Concrete

The usability of low-cost iron wire fiber for the reinforcement of hot asphalt mixtures was investigated with experimental tests in this study. Five mixtures having different fiber content of 1%, 3%, 5%, 7%, 9% and control mixtures were prepared. Characteristic properties of bitumen, aggregate and iron wire used in the mixtures were determined by thermogravimetric analysis (TGA), conventional bitumen tests, conventional aggregate tests and metal tensile tests. After optimum bitumen rate was determined, Marshall Stability Test, Cantabro Tests were performed in order to measure perfomance of the mixtures. Additionaly, moisture susceptibility of samples was determined with indirect tensile test. As a result of indirect tensile tests, indirect tensile strength (St) and indirect tensile strength ratio (ITSR) values were calculated. The results of the investigations indicate that the addition low-cost iron fiber in the amount of 1%-3% improved performance of asphalt mixtures. When the used fiber rate was increased more than 3%, clustering created by fibers was observed by using stereo-microscobe. Consequently, air voids were increased and bitumen-aggregate interaction was decreased. Increasing fiber ratio especially, at 7-9 percent caused compressing, durability and stability problems in the mixture.