Performance graded sulfur modified asphalt compositions for super pave compliant pavements
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, and sulfur. The compositions are capable of being performance graded.
Claims33
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 asphalt concrete composition comprising:
- a binder comprising:
- a polyphosphoric acid, the polyphosphoric acid being present in an amount effective to provide high temperature stiffness for the composition;
- a polymer having a saturated backbone with macromolecular modifications, the polymer being present in an amount effective to provide sufficient lubrication for the composition;
- sulfur being present in a range of from about 20 wt. % to about 50 wt. % of the binder;
- and
- asphalt;
- and
- an aggregate selected from the group consisting of coarse filler, fine filler, mineral filler, and combinations thereof.
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 binder comprising:
- a polyphosphoric acid, the polyphosphoric acid is present in a range of from about 0 wt. % to about 2.0 wt. % of the binder;
- a polymer having a saturated backbone with macromolecular modifications, the polymer having a saturated backbone with macromolecular modifications being present in a range of from about 0 wt. % to about 5 wt. % of the binder;
- sulfur, the sulfur being present in a range of from about 20 wt. % to about 50 wt. % of the binder;
- and
- asphalt.
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 a binder comprising a polyphosphoric acid, a polymer having a saturated backbone with macromolecular modifications, asphalt and sulfur, the polyphosphoric acid being present in an amount effective to provide high temperature stiffness for the binder, the polymer being present in an amount effective to increase viscosity of the binder, and the elemental sulfur being present in a range of from about 20 wt. % to about 50 wt. % of the binder;
- and
- b. combining the binder with aggregate to produce the asphalt concrete composition.
Dependencies are inferred from the claim text.