Rheological characteristics of SBR and NR polymer modified bitumen emulsions at average pavement temperatures

The effects of SBR and NR polymers on characteristics of various bitumen emulsion binders were analyzed. Binders were tested applying fundamental and rheological bitumen tests. Temperature sweep and Multiple Stress Creep and Recovery testing were performed to characterize the rheological properties in linear and non-linear modes. In linear region, the presence of polymers improved stiffness and elastic properties of residual binders of the bitumen emulsions appreciably. Comparing the behavior of the two polymers in non-linear region resulted that SBR was more sensitive to applied stresses. Additionally, NR latex increased stiffness values of the emulsion residues substantially; while; their elastic properties were remained unchanged.