Effect of Aging on the Rheological Behaviors of SBS-Modified Asphalt with Thermochromic Materials
Abstract
The influences of different types (red, black, and blue) and dosages (2 % and 4 %) of thermochromic materials on rheological and aging resistance of styrene-butadiene-styrene copolymer (SBS)–modified asphalt (SBSMA) were studied. Rheological properties at high and low temperatures for thermochromic asphalt binder (TAB) were characterized by a dynamic shear rheometer and bending beam rheometer. The complex modulus of SBSMA decreased after the thermochromic powder was added, which indicated that thermochromic materials deteriorated the high-temperature rutting resistance of SBSMA, and the dosage of 2 % blue thermochromic powder had the least influence on the high-temperature performance of SBSMA. Instead, adding powders into SBSMA greatly improved the low-temperature deformation and relaxation capacity of SBSMA. Among all of the samples, the binder added with 2 % blue thermochromic powder showed the widest performance grade range. Rheological aging indexes were utilized to evaluate the antiaging performances of SBSMA. Compared with those of SBSMA, the rheological aging indexes of TAB were much smaller, which presented that thermochromic materials are able to strength the antiaging performances of SBSMA. In general, the binder added with 2 % red thermochromic powder showed the best aging resistances against thermal and photooxidation aging simultaneously, followed by the binder added with 4 % red thermochromic powder.