Investigation of the effect of recycled polyethylene terephtalate (PET) on properties of bitumen and hot mix bituminous

In this study; the effects of polyethylene terephthalate (PET) obtained by recycling on bitumen and bituminous hot mixtures as an additive were investigated. For this purpose, 2.5% Triethanolamine (TEO) by weight of bitumen was added to pure bitumen having penetration class B 70/100 in order to provide a good interaction between bitumen and PET. Subsequently, the modification was completed by adding 2%, 4%, 6%, 8% and 10% PET based on the weight of bitumen. The physical properties of the obtained binders were determined by conventional tests, rheological properties were determined by dynamic shear rheometer(DSR), beam bending rheometer(BBR) and rotational viscometer(RV) tests. SEM, XRD and FTIR Spectroscopy analyzes were investigated of binders. Samples were prepared by Marshall mix design method using modified binders. Marshall Stability, Permanent Marshall Stability (RMS), Indirect Tensile Stiffness Modulus (ITSM), Indirect Tensile Strength (ITS) and Creep Stiffness tests were performed on the samples. According to the results obtained; ıt has been observed that the PET additive reacts with bitumen with the help of TEO, and in the certain stage hardens bitumen with increasing amount of additive, but then softens again. Although the PET-added binders harden with respect to the pure binder, the mixing and compression temperatures did not change significantly and the high and low temperature performance classes remained constant. As a result of the mixture tests, Marshall stability and ITSM values were found to be highest in 6% PET mixtures, RMS, indirect tensile strength ratio and creep stiffness values were highest in 8% PET mixtures.