| Summary: | Layered silicates, as bitumen modifiers, have received increasing attention. The main objective of this study was to evaluate the influence of layered silicates on bitumen properties. For this study, montmorillonite (MMT), rectorite (REC), organic montmorillonite (OMMT), and organic rectorite (OREC) were selected. The layered structure type of layered silicates was characterized by SEM (scanning electron microscope) and XRD (X-ray diffraction diffractometer). Tests for determining high-temperature properties included viscosity, DSR (dynamic shear rheometer), and TG (thermogravimetry) tests, and studies for determining the low-temperature properties were conducted by BBR (bending beam rheometer) and DSC (differential scanning calorimetry) tests. Our results show that MMT, REC, OMMT, and OREC were all intercalated structures. OREC had the largest <i>d<sub>001</sub></i> interlayer space, followed by REC, OMMT, and MMT. OREC improved the high-temperature property of virgin bitumen more effectively than OMMT. Meanwhile, REC-modified bitumen exhibited a high-temperature property similar to OMMT-modified bitumen. When compared with REC and OREC, MMT and OMMT were less efficient in reducing the low-temperature properties of virgin bitumen, and OMMT was the least efficient. Therefore, it can be concluded that the nature of pristine layered silicates has a great impact on the high- and low-temperature properties of bitumen. Moreover, organic treatment can simultaneously improve the high- and low-temperature properties of layered silicate-modified bitumens.
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