Modification of asphalt by synthesising a new additive with boron-based rosin and investigation of the mixture performance

This thesis, a new additive was obtained by chemically synthesising boron oxide, one of the boron derivatives that our country has an important reserve, and natural colophane resin obtained from pine trees in the laboratory, and the usability of this synthesis additive as asphalt modifier and its performance properties on asphalt binder were investigated. The additive was determined to be compatible with the binder after the structural characterisation of the resulting Boron Oxide and Resin Compound (BORB) was evaluated by FT-IR, SEM, XRD, and DSC/TG analytical methods. Modified binders were produced for the study by adding 0.5%, 1%, 1.5%, 1.5%, and 3% by weight additives to B 50/70 penetration class asphalt binder. While the physical properties of base and modified binders were determined by conventional tests, their rheological properties were determined by Superpave experiments such as dynamic shear rheometer (DSR), rotational viscometer (RV), rotational thin film ageing (RTFOT), pressure ageing chamber (PAV), beam bending rheometer (BBR). In addition, Multiple Stress Creep-Recovery (MSCR) and Linear Amplitude Scanning (LAS) experiments were also performed on the binders. Mix specimens were produced according to the Marshall design with the modified bituminous binder at the specified BORB additive ratios and the mechanical properties of the specimens were determined by Marshall Stability and Yield, Indirect Tensile Strength, Modified Lottman, Dynamic Creep and Indirect Tensile Fatigue tests. From the experimental results obtained, it was determined that the binder consistency and rutting performance improved at high temperatures as the BORB additive amount increased, while the effect of the additive amount decreased at medium and low temperatures. It was found that the additive's presence enhanced the base binder's adhesion and cohesion capabilities, fatigue strength, elastic behavior, and temperature sensitivity. When the experiments on the binder and mixtures were considered as a whole, it was seen that the binder modified with 1% BORB additive rate had the best physical, rheological and mechanical results.