Evaluation the effect of sewage sludge ash on physical and rheological properties of bitumen

In this study, the physical and rheological properties of bitumen containing different percentages of sewage sludge ash (SSA) were evaluated. For this purpose, the sewage sludge was burned at 900˚C, and remaining ash was used as bitumen additive in 0, 2.5, 5, and 7.5 percent by the weight of base bitumen. The penetration test, softening point test, ductility test, rotational viscometer test, dynamic shear rheometer test, and bending beam rheometer test were performed to evaluate the physical and rheological properties of different samples. The results showed that by increasing the SSA, the penetration and ductility of bitumen decrease, and the softening point increases. The addition of SSA increases the rotational viscosity of bitumen, but it is still much less than the allowable value of 3 Pascal. Second. The dynamic shear rheometer test showed that the addition of SSA to bitumen increases the rutting resistance and decreases the fatigue life of specimens. Also, the addition of SSA increases the potential of low temperature cracking.