Sulfur modified asphalt for warm mix applications
AssigneeSaudi Arabian Oil Company
InventorsMilind M. Vaidya, Anwar H. Khawajah, Rashid M. Othman, Laurand Lewandowski
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Abstract
Disclosed herein are an asphalt concrete mixture, an asphalt binder composition, and methods of preparing the related compositions. The asphalt binder compositions include a polyphosphoric acid, a macromolecular polymer having a saturated backbone with macromolecular modifications, sulfur, and non-surfactant additives based on wax chemistry. The compositions are capable of being performance graded and being used in warm mix asphalt applications.
Claims27
A highly loaded sulfur-modified asphalt binder composition for use with asphalt concrete for improved properties relative to high temperature rotational viscosity without a reduction in dynamic shear properties, the asphalt binder comprising:
- a. a polyphosphoric acid present in a range of up to 2 wt. % of the asphalt binder composition;
- b. a macromolecular polymer having a saturated backbone with macromolecular modifications being present in a range up to 5 wt. % of the asphalt binder composition;
- c. sulfur, the sulfur being present in a range of about 20 wt. % to about 50 wt. % of the binder composition, where the amount of sulfur being effective to at least partially emulsify in the composition;
- d. non-surfactant additives based on wax chemistry being present in an amount sufficient to provide a lubricating effect on the asphalt binder composition;
- and
- e. bitumen.
A method of preparing an asphalt concrete composition having high sulfur load with improved properties relative to high temperature rotational viscosity without a reduction in dynamic shear properties, the method comprising the steps of:
- a. preparing an asphalt binder, where the asphalt binder comprises:
- (1) a polyphosphoric acid present in an amount effective to increase stiffness at lower mixing temperatures,
- (2) a macromolecular polymer having a saturated backbone with macromolecular modifications present in an amount effective to increase viscosity of the composition so that it can be used in warm mix applications,
- (3) sulfur present in loadings ranging from 20 wt. % to 50 wt. % of the asphalt binder, where the amount of sulfur is effective to at least partially emulsify in the composition,
- (4) non-surfactant additives based on wax chemistry, the non-surfactant additives based on wax chemistry being present in an amount sufficient to provide a lubricating effect on the composition, and
- (5) bitumen;
- and
- b. combining the asphalt binder with aggregate such that the asphalt concrete is produced.
Dependencies are inferred from the claim text.