Among the more important uses are road mixing operations, stockpiling mixes, and spray applications such as prime. RC and MC types of cutback asphalts are used in a variety of highway construction. Cutback asphalts can be used with cold aggregates, with a minimum of heat. Some are quite fluid at ordinary atmospheric temperatures and others are somewhat more viscous and may require heating to melt them enough for construction operations. The degree of fluidity results in several grades of cutback asphalt. The degree of fluidity obtained in each case depends on the grade of asphalt cement/binder, volatility of the solvent, and proportion of solvent to binder. (At present, SC is not used in Virginia.) This term originated in earlier days when asphaltic residual oil was used to give roads a low-cost, all-weather surface. Slow-Curing (SC) – asphalt and an oily diluent of low volatility Slow-curing (SC) asphalts are often called road-oils.Medium-Curing (MC) – asphalt and a solvent of intermediate volatility or medium distillate, generally in the kerosene boiling point range.Rapid-Curing (RC) – asphalt and a volatile solvent or light distillate, generally in the gasoline or naphtha boiling point range.On the basis of relative speed of evaporation, cutback asphalts are divided into three types: Solvents of lower volatility evaporate more slowly. If the solvent used in making the cutback asphalt is highly volatile it will quickly escape by evaporation. Petroleum solvents used for dissolving binder are sometimes called distillate, diluent, or cutter stock. Their uses included dust control, pavement maintenance, construction (chip seal) and cold mix patching. Some are thin enough to be used as prime oil or tack, while others must be heated for use. This page discusses basic information on these liquid asphalts and their use for “tack” and “prime” applications.Ĭutback asphalt is simply a combination of asphalt cement and petroleum solvent. By suspending it in water through the emulsification process (known as “emulsified asphalt” or “asphalt emulsion”)Ĭutback asphalt and emulsified asphalts are called liquid asphalts to distinguish them as a group from normal asphalt cement/binder.By blending it with a light petroleum solvent (known as “cutback asphalt” or “cutback”).By heat, this is what happens at an asphalt concrete plant (known as “asphalt cement” or “asphalt binder”) Click here to go to the Asphalt Cement/Binder page.Refined asphalt is graded for specific engineering properties and can be liquefied in three ways. Asphalt is the heaviest part of the crude-what’s left after all the volatile, light fractions are distilled off for products such as gasoline. Asphalt occurs naturally in a few places in the world, but most of the asphalt used today for paving comes from petroleum crude oil. It may be found in natural deposits or may be a refined product it is a substance classed as a pitch. Asphalt (sometimes called “liquid asphalt”, “asphalt cement” or “asphalt binder”) is a sticky, black and highly viscous liquid or semi-solid form of petroleum.
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