Investigation of usability of mineral fiber in stone mastic asphalt

Stone mastic asphalt (SMA) pavements were developed to prevent rutting, abrasion, and various pavement deteriorations and to increase the life of the superstructure. They certainly stand out with their high grain contact, stone-stone interlocking ability, and high bitumen ratio on heavy-traffic roads with heavy axle loads. This study aimed to investigate the effects of basalt fiber in different sizes, partly cellulose, and partly basalt fiber addition, on the drain down of the performance of bitumen and the changes in rutting performance as additives to stone mastic asphalt pavements. To determine the absorption performance of bitumen fiber additives, 19 mixtures were pre-pared and the Schellenberger drain down test was carried out. The results, including the witness mixture, showed that the Schellenberger test result was below the value specified in the motorway technical specification by a maximum of 0.3%. For the Hamburg wheel tracking test (HWTT) additive and witness mixtures were prepared at optimum bitumen ratios using a gyratory compactor. HWTT was applied to the mixtures numbered 1, 4, 10 and 14, which have the best the Schellenberger drain down performance, and the witness sample. As a result of the experiments, the highest rutting deformation was measured at the samples using 12mm basalt fiber at the rate of 0.2%. The lowest rut deformation was measured in samples containing 12mm basalt fiber at the rate of 0,3% and cellulose fiber at the rate of 0.2%. It was determined that the combined use of cellulose and basalt fiber mixture improved the resistance against rutting by 37%. As a result of the HWTT, it was determined that stone mastic asphalt mixtures with basalt and cellulose fiber additives were more resistant to rutting than the witness and basalt-only mixtures.