Stress relaxation behavior of asphalt emulsion residue

It is well known that the mechanical behavior of the binder available in a pavement completely controls the mechanical response characteristics of the asphalt layers. Within the context of cold mix asphalt construction, it assumes considerable significance due to the complex emulsion breaking process and the resulting asphalt emulsion residue left in the pavement. This investigation involves using two different asphalt emulsion residue recovery process in the laboratory and testing the stress relaxation behavior of the residue. Two standard emulsions, namely slow setting and rapid setting type were used for asphalt residue recovery. Two recovery processes were used to recover asphalt from the asphalt emulsion, the first one involved air drying at room temperature, and the second one involved the use of rolling thin film oven at a temperature of 60 degree C for 120, 240 and 360 minutes. Additionally PAV experiments were conducted on the slow setting and rapid setting residues obtained from RTFOT recovery process and compared with the PAV aged parent asphalt under identical conditions. The recovered residue was tested for its stress relaxation behavior in a dynamic shear rheometer for different strains and temperatures. It was seen that the emulsion residue recovery process plays a major role on the rheological properties. It was also seen that emulsified asphalt residue exhibit considerably 'stiffer' behavior when compared with parent asphalt. © 2008 Taylor & Francis Group, London.