Bituminous composition
This invention relates to bituminous compositions and methods of producing the same. More particularly, the invention relates to the production of bituminous compositions formulated with performance-graded bitumen-containing solvent-free bitumen emulsions which exhibit controllable, temperature-dependent interfacial rheology. When employed in paving applications, these bituminous compositions develop adhesive strength and load-bearing strength properties at rates comparable to traditional hot mix paving compositions and at rates faster than traditional cold mix paving compositions.
1. A bituminous composition comprising, based on total weight of the bituminous composition:
(a) hard bitumen in an amount of 1.0% to 7.5% by weight, the hard bitumen being characterized by a penetration number of 100 dmm or less at 25° C. as determined according to the American Association of State Highway and Transportation Officials (AASHTO) Method T49;
(b) emulsifier in an amount of 0.001% to 0.2% by weight, wherein the emulsifier has a Hildebrand solubility parameter of at least 19 (MPa) 1/2 ;
(c) water in an amount of 0.46% to 5.0% by weight; and
(d) aggregate in an amount of 90.0% to 98.0% by weight, the aggregate having an aggregate surface that is wetted with the hard bitumen,
wherein the bituminous composition is at a temperature ranging from 50° C. to 120° C.
2. The bituminous composition of claim 1 wherein the temperature ranges from 55° C. to 100° C.
3. The bituminous composition of claim 1 wherein the temperature ranges from 60° C. to 80° C.
4. The bituminous composition of claim 1 stored in a closed system.
5. The bituminous composition of claim 1 , wherein the hard bitumen is modified with a chemical comprising at least one member selected from the group consisting of natural rubbers, synthetic rubbers, plastomers, thermoplastic resins, thermosetting resins, elastomers, and combinations thereof.
6. The bituminous composition of claim 1 , wherein the hard bitumen includes a modified bitumen comprising at least one member selected from the group consisting of styrene-butadiene-styrene, styrene-butadiene-rubber, polyisoprene, polybutylenes, butadiene-styrene rubbers, vinyl polymers, ethylene vinyl acetate, ethylene vinyl acetate derivatives, sulfur-modified bitumen, acid-modified bitumen, and combinations thereof.
7. The bituminous composition of claim 1 wherein the emulsifier includes an amphoteric emulsifier.
8. The bituminous composition of claim 1 wherein the emulsifier includes a cationic emulsifier.
9. The bituminous composition of claim 1 wherein the aggregate includes a member selected from the group consisting of dense-graded aggregate, gap-graded aggregate, open-graded aggregate, reclaimed asphalt pavement, and combinations thereof.