The invention relates to a process for preparing foamed polymer-modified bitumen compositions and to the use thereof for the production of asphalt. The invention also relates to foamed polymer-modified bitumen compositions obtainable by this process. Furthermore, the invention relates to a process for producing an asphalt composition and to the use thereof in road applications. The process for the preparation of the foamed polymer-modified bitumen composition comprises the following steps: i) Heating and pressurizing a bitumen to obtain a hot flowing bitumen stream, ii) Injecting under pressure an aqueous polymer dispersion into the hot flowing bitumen stream obtained in step i), to obtain a pressurized flowing mixed stream of the bitumen and the aqueous polymer dispersion; iii) Expanding the flowing mixed stream, in particular to atmospheric pressure, such that the water contained in the aqueous polymer dispersion vaporizes and foams the mixed stream to obtain a foamed polymer-modified bitumen.

The present disclosure relates to the field of so-called “spreading” emulsions of hydrocarbon binder, in particular cationic emulsions of hydrocarbon binders. Such emulsions are useful in the preparation of surface dressings, tack coats, fog seal type surface courses and paver seams. The use of an anionic polymer to improve immediate adhesiveness of a cationic emulsion of hydrocarbon binder to solid particles is particularly described.

Pavement aging can be reduced by applying to an asphalt-containing pavement a topcoat layer or a surface treatment containing asphalt binder emulsion with sterols.

Asphalt emulsions, methods of forming asphalt emulsions, and composite pavement structures formed from the asphalt emulsions are provided herein. In an embodiment, an asphalt emulsion includes a base asphalt component, water, and an oxidized high density polyethylene. The base asphalt component is present in an amount of from about 15 to about 70 weight %, the water is present in an amount of at least about 25 weight %, and the oxidized high density polyethylene is present in an amount of from about 1 to about 20 weight %, where all amounts are based on the total weight of the asphalt emulsion. The oxidized high density polyethylene has an acid value of from about 5 to about 50 mgKOH/g. The asphalt emulsion is free of aggregate and other mineral materials.

Asphalt emulsions, methods of forming asphalt emulsions, and composite pavement structures formed from the asphalt emulsions are provided herein. In an embodiment, an asphalt emulsion includes a base asphalt component, water, and an oxidized high density polyethylene. The base asphalt component is present in an amount of from about 15 to about 70 weight %, the water is present in an amount of at least about 25 weight %, and the oxidized high density polyethylene is present in an amount of from about 1 to about 20 weight %, where all amounts are based on the total weight of the asphalt emulsion. The oxidized high density polyethylene has an acid value of from about 5 to about 50 mgKOH/g. The asphalt emulsion is free of aggregate and other mineral materials.

Pavement aging can be reduced by applying to an asphalt-containing pavement a topcoat layer or a surface treatment containing asphalt binder emulsion with sterols.

A paving mixture for application to a surface and a method for the same. The mixture comprises a binding material layer applied to the surface to form a base layer on the surface, and an aggregate material layer applied on top of the binding material layer. The binding material layer can be applied in an amount of at most 0.125 gallons/yd.sup.2. The aggregate material layer contains an asphalt mixture that provides a road surface. The aggregate material layer and the binding material layer can be combined on the surface within 30 seconds of application of the binding material layer. Additionally, multiple paving mixtures may be applied to the surface.

A paving mixture for application to a surface and a method for the same. The mixture comprises a binding material layer applied to the surface to form a base layer on the surface, and an aggregate material layer applied on top of the binding material layer. The binding material layer can be applied in an amount of at most 0.125 gallons/yd.sup.2. The aggregate material layer contains an asphalt mixture that provides a road surface. The aggregate material layer and the binding material layer can be combined on the surface within 30 seconds of application of the binding material layer. Additionally, multiple paving mixtures may be applied to the surface.

A sustainable pavement is constructed by creating a construction structure for a hot mix asphalt (HMA) pavement according to a pavement project; calculating a greenhouse gas (GHG) emission of the HMA pavement; performing a sustainable construction on the HMA pavement to modify one or more layers in the HMA pavement to form a sustainably constructed pavement; calculating a GHG emission of the sustainably constructed pavement; and obtaining a carbon reduction by comparing the GHG emissions of the HMA pavement and the sustainably constructed pavement.

A sustainable pavement is constructed by creating a construction structure for a hot mix asphalt (HMA) pavement according to a pavement project; calculating a greenhouse gas (GHG) emission of the HMA pavement; performing a sustainable construction on the HMA pavement to modify one or more layers in the HMA pavement to form a sustainably constructed pavement; calculating a GHG emission of the sustainably constructed pavement; and obtaining a carbon reduction by comparing the GHG emissions of the HMA pavement and the sustainably constructed pavement.