Evaluating the effect of organic reagents on short-term aging resistance of the organic rectorite asphalt by multi-indicators

Abstract

The structure of organic reagents has an effect on the properties of the OREC modified asphalt. This study selected dodecyl trimethyl ammonium chloride (1231), lauryl dimethyl benzyl ammonium chloride (1227) and stearyl trimethyl ammonium chloride (1831) to modify Na-rectorite (Na-REC) and then prepared OREC modified asphalts. The objective is to evaluate the effect of organic reagents on short-term aging resistance of the OREC modified asphalt. Physical properties, rheological properties and FTIR tests were conducted. Results indicate that the introduction of Na-REC and ORECs improves the short-term aging resistance of base asphalt, and organic modifications to Na-REC have better effect. 1831-reagent endows OREC with the strongest restriction on oxygen penetration and then leads to the best short-term aging resistance of OREC modified asphalt, followed by 1227-reagent, 1231-reagent. Aging sensitivities shown by various rheological indices were compared. The result demonstrates that the complex modulus aging index and RAI (rutting resistance factor aging index) are most sensitive to rolling thin film oven aging, followed by VAI (viscosity aging index), phase angle aging index. Moreover, the atomic force microscope (AFM) was employed to evaluate the microstructure of asphalt samples. The result demonstrates that there is some absorption of Na-REC and ORECs to asphaltene, and ORECs probably hinder the transformation of asphalt from some lightweight compounds to asphaltenes more effectively than Na-REC during RTFO aging.