Investigation on Thermo-Rheological Properties andStability of SBR Modified Asphalts ContainingPalygorskite Clay

摘要

One problem of polymer-modified asphalts(PMAs) is the poor compatibility between polymer andasphalts. In this article, the effects of palygorskite clay (PC)and organomodified palygorskite clay (OPC) on the rheolog-ical and morphological properties of styrene butadiene rub-ber (SBR) modified asphalts are investigated. The dynamicmechanical analysis (DMA) of PC and SBR/PC (OPC) modi-fied asphalts before and after ageing has been characterizedby dynamic shear rheometer (DSR). The results indicate thatthe degree of SBR modification is a function of asphalt-poly-mer compatibility. When the polymer concentration ishigher, it produces a highly elastic network which increasesthe viscosity, complex modulus, and elastic response of themixture, particularly at high service temperatures. However,ageing of the SBR and SBR-PC mixtures result in a decrease n the elastic response of the modified asphalts. It also havebeen confirmed that the morphology observed by optical mi-croscopy and scanning electron microscope (SEM) revealedthe better compatibility between SBR/PC and asphalt. Thestorage stability of binder is improved significantly. Com-pared with PC, OPC shows better effect in improving visco-elastic properties and rutting resistance of the mixture,which contributes to the better improvement of interfacialadhesion based on larger size between layers in OPC-modi-fied asphalts.