Natural polyphenolic-containing vegetable extract modified bitumen and anti-stripper compositions, method of manufacture and use

The addition of from about 0.1 to about 1 parts by weight of a natural polyphenolic-containing vegetable extract (NPVE) per 100 parts of bitumens (particularly asphalt), coal tar, or other high boiling tars containing mixtures of aliphatic and aromatic hydrocarbons modifies the characteristics of the treated product to enhance its performance as hot-melt adhesives, coatings, sealants, roof-coatings, and road-coatings as compared to the base bitumen. The NPVEs are naturally occurring, are extracted from plants and include quebracho, chestnut, wattle and sumac. By forming the ammonia salt of NPVE (ammonium/NPVE) and adding it to a base or NPVE-modified bitumen, the characteristics of increased adhesion and resistance to stripping is observed. Surprisingly, the addition of commercially available anti-stripping agents to an ammonium/NPVE-modified bitumen results in a modified-bitumen having a stripping resistance greater than either of the additives alone. The ammonium/NPVE salt anti-stripping agent may be mixed directly with the tars or put into a water solution and then added to hot tars with the water being driven off. Alternately, the ammonium/NPVE salt anti-stripping agent may be applied to the aggregate to be mixed with the asphalt so as to produce a pretreated, anti-stripper coated aggregate.