ásphaltos

Asphalts are a family of viscous, black, sticky substances that exist as natural deposits or are produced from crude oil refining. They are used mainly as binders in road pavements and as waterproofing materials in roofing and construction. The term encompasses bitumen and asphalt, sometimes including natural asphaltites.

Natural asphalts occur as seeps, pools, or substantial deposits in various regions and may contain minerals and organic material. Petroleum asphalts are produced by processing the heavy residues of crude oil through vacuum distillation; they may be further treated by air oxidation and blended with polymers to improve elasticity and temperature performance.

Classification and properties: paving-grade asphalts are formulated for road asphalt with properties such as penetration, softening point, and viscosity, whereas roofing asphalts prioritize flexibility and low-temperature performance. Polymer-modified asphalts are common for higher performance applications.

Uses and recycling: road construction and maintenance; asphalt concrete binders; roofing shingles; waterproofing membranes; sealants and adhesives. Reclaimed asphalt pavement can be recycled into new mixes, reducing resource use.

Environmental and safety considerations: handling hot asphalt carries burn and inhalation risks; emissions include volatile organic compounds. The industry emphasizes energy efficiency, pollution controls, and recycling.

History: asphalt has been used since ancient times, with natural bitumen employed in building and waterproofing. Modern practice grew with oil refining in the 19th and 20th centuries, enabling widespread road paving and roofing applications.