Yasser Hamidi - Kermen, Khajo street, National iranian oil products distribution company in the kerman region
Amir Sarrafi - Department of chemical engineering, Bahonar university of kerman
Majid Tahmooresi - International center for since, high technology & environmental sinces,kerman

Present research has investigated the effect of crumb rubber and calcium carbonate on bitumen properties. Different amounts of materials have been mixed in a mixer under different conditions. Penetration degree, softening point and viscosity experiments have been performed on obtainedsamples. At first, different conditions of adding crumb rubber such as weighted percentage, temperature of mixing and mixing time. In the next step, calcium carbonate was added to the selected mixed bitumen in different added amount weighted percentage. Finally bitumen with 16%crumb rubber and 6% calcium carbonate has been selected as the best quantities for additives.

bitumen, penetration degree, softening point, crumb rubber, calcium carbonate