EFFECTS OF EVOTHERM ON CONVENTIONAL AND RHEOLOGICAL PROPERTIES OF CRUMB RUBBER MODIFIED BINDER

The combined usage of additive in the same binder is a new research area among the highway engineers. In this study the rheological and conventional properties of binders produced with crumb rubber (CR) and Evotherm which is a warm-mix additive were evaluated and compared with the neat bitumen. The binders were prepared in 8 different combinations. CR and Evotherm contents were kept constant at 10% and 0.7% by weight of neat bitumen, respectively. Penetration, softening point, rotational viscometer (RV), dynamic shear rheometer (DSR) and bending beam rheometer (BBR) test were conducted to base and modified binders. In conclusion it was determined that use of CR individually induces an increase in viscosity, softening point and complex modulus with the increase of additive content. It also contributes to low temperature performance by providing low stiffness and high m-value. On the other hand the use of Evotherm both individually and with CR modification do not induce positive or negative variation in performance of binder in terms of conventional and rheological tests. However it can provide just a bit benefit on flexible behavior of CR modified binder by offering lower phase angles in DSR test.