Effects of geopolymer obtained from ferrochrome slag on the performance of bituminous hot mixes

In this study, the effects of geopolymer obtained from ferrochrome slag (FeCR), an industrial waste material that is released at high rates in the world and in our country, on the performance of bituminous hot mixtures (BSK) were investigated. For this purpose, firstly, the characteristic properties of crushed limestone aggregate and pure B 50/70 bitumen were determined. Then, hot mix samples were prepared using the Marshall mix design method and the optimum bitumen content (OBI) of these samples was determined. After the OBI ratio was determined, based on this ratio, the filler ratio in the hot mixture was reduced by 25%, 50%, 75% and 100% by weight and FeCR was added, and 8% alkaline activator (AA) sodium silicate was added to these mixtures and geopolymer-added mixture samples were prepared. All prepared mixture samples were subjected to Marshall stability and flow, static and dynamic creep, indirect tensile stiffness modulus (ITSM) and indirect tensile fatigue tests. According to the test results obtained, it was observed that the stability of the mixture samples with 75% geopolymer (bitumen+aggregate+ FeCR+AA) increased, their resistance to permanent deformations improved and their fatigue life increased significantly. As a result, it has been determined that FeCR can be used instead of fillers in BSKs and FeCR-doped geopolymers can have an improving effect on the performance properties of BSKs. Keywords: Industrial waste, Ferrochrome slag, Marshall stability, ITSM, Permanent deformatio