Download or read book Characterization of Styrene-Butadiene-Styrene Polymer Modified Bitumens?Comparison of Conventional Methods and Dynamic Mechanical Analyses written by X. Lu and published by . This book was released on 1997 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rheological properties of styrene-butadiene-styrene polymer (SBS) modified bitumens were studied using conventional test methods (penetration, softening point, kinematic viscosity and Fraass breaking point) and dynamic mechanical analysis (DMA). The study indicated that SBS modification improved the viscoelastic properties of bitumens, which can be demonstrated using DMA but not conventional methods. Significantly improved properties of binders included increased dynamic mechanical moduli and decreased phase angle at high temperatures, as well as reduced complex modulus and increased phase angle at low temperatures. SBS modification also caused reductions in glass transition temperature, Fraass breaking point, and temperature susceptibility. The degree of improvement was observed to be influenced by bitumen source/grade and polymer content/structure. Comparison showed that certain relationships exist between parameters obtained using conventional methods and DMA, such as between penetration and complex modulus, kinematic viscosity and complex viscosity, and Fraass breaking point and glass transition temperature. However, the main conclusion of the study is that conventional test parameters such as penetration and softening point are not suitable for characterization of rheological properties of SBS modified bitumens.