مرکز منطقه ای اطلاع رساني علوم و فناوري - Determination of the mixing and compacting temperatures of pure and polymer modified binders by rotational viscosimeter test

Abstract :

It is of capital importance with respect to ease of construction and service life of the pavement that bituminous binders possess the right temperature during the course of mixing with the aggregate and compaction. Binder temperatures colder than this ideal level lead to excessively high void contents, while higher temperatures lead to excessive ageing of the binder coupled with excessive compaction. In this study, pure and modified binders containing two different proportions of SBS were analyzed. Firstly, penetration and softening point tests were conducted on the pure and modified bitumens prior to and after short term ageing. Thereby, the influence of SBS admixture on stiffness of the bituminous binder and heat sensitivity were determined. Afterwards, the temperatures of mixing with aggregate and compaction for pure and SBS modified binders were determined by the assistance of rotational viscosimeter test results obtained in accordance with AASHTO TP48 standard. In light of the results of the rotational viscosimeter test, viscosity values of the binders were found to be increasing at both 135ºC and 165ºC of temperature with rising levels of SBS content. Finally, it was determined that the compaction and mixing temperatures of the binders increased depending on the value of viscosity.