Hot mix asphalt and method of preparation thereof
AssigneeChemical Lime Company
InventorsFred R. Huege, Robin E. Graves, Timothy L. Salter, Patrick Shields, Norman L. Hains
Life of this patent
Estimating the term…
Abstract
A method is shown for improving the properties of hot mix asphalt by treating the aggregate which is combined with bituminous binder with lime. A hot quicklime slurry is produced by slaking quicklime with water at the site of the hot mix asphalt plant using a portable mixing tank. The hot quicklime slurry is then applied to the aggregate, the aggregate is dried and combined with the binder to produce the hot mix asphalt.
Claims15
In a method of preparing a hot mix asphalt paving material containing sand, mineral aggregate material and asphalt binder, the improvement comprising a method of treating the mineral aggregate material to promote adhesion between the mineral aggregate material and the asphalt binder, the method comprising the steps of:
- mixing together in a slurry mixing tank unslaked quicklime and an aqueous slaking medium to form a hot quicklime slurry by exothermic reaction, the resulting quicklime slurry having a lime solids content greater than about 30% by weight, based upon the total weight of the quicklime slurry;
- and
- treating the mineral aggregate material with the hot quicklime slurry while the slurry is at a temperature above ambient.
In a method of preparing a hot mix asphalt paving material containing sand, mineral aggregate material and asphalt binder, wherein the mineral aggregate used in forming the hot mix asphalt composition is treated with an alkaline material to promote adhesion between the mineral aggregate material and the asphalt binder, the improved method comprising the steps of:
- mixing together in a slurry mixing tank unslaked quicklime and an aqueous slaking medium to form a hot quicklime slurry by exothermic reaction, the resulting quicklime slurry having a lime solids content greater than about 40% by weight, based upon the total weight of the hot quicklime slurry;
- applying the hot quicklime slurry to the mineral aggregate material;
- drying the mineral aggregate material;
- combining the treated and dried mineral aggregate material with the asphalt binder to form a hot mix asphalt.
In a method of preparing a hot mix asphalt paving material containing sand, mineral aggregate material and asphalt binder, wherein the mineral aggregate used in forming the hot mix asphalt composition is treated with an alkaline material to promote adhesion between the mineral aggregate material and the binder, the improved method comprising the steps of:
- mixing together in a slurry mixing tank unslaked quicklime and an aqueous slaking medium to form a hot quicklime slurry at elevated temperature above ambient by exothermic reaction, the resulting hot quicklime slurry having a lime solids content greater than about 30% by weight, based upon the total weight of the quicklime slurry;
- applying the hot quicklime slurry before said slurry cools below ambient temperature and while said hot slurry is at a temperature above ambient to the mineral aggregate material;
- drying the aggregate material;
- combining the treated and dried mineral aggregate material with the asphalt binder to form a hot mix asphalt.
Dependencies are inferred from the claim text.