Asphalt, cut back

Asphalt, cut back Cut-backs Bitumen Pencil pitch Pitch prill Road asphalt Road asphalt or tar liquids Tars, liquid, 3.2, 3.3 Tars, liquid, including road asphalt and oils, bitumens and cut backs, 3... 

Asphalt cut back n. Asphalt plus thinner asphalt solution asphalt coating formed by dissolving asphalt. Usmani AM (1997) Asphalt science and technology. Marcel Dekker, New York. 

Table 6. Three Types of Uquid Asphalt Made by Cutting Back with Petroleum Diluents...

Asphalt Manufacture Saleable asphalts are produced from the residua of selected crudes. The residuum itself may be sold as straight reduced cuts to make it easier to handle, producing the so called cut-back asphalts. Another variation is air blown or oxidized asphalts for improved tenacity, greater resistance to weathering, and decreased brittleness. Emulsified asphalts are made for application at relatively low temperatures. 

This method covers the decn of the flash point, by Tag closed tester, of liquids with a viscosity of below 45 SUS at 100F (37.8 C) and a fl pt below 200 F (93 C) except cut-back asphalts and those liquids which tend to form a surface film under test conditions Note 1 For the closed cup fl pt of liquids with... 

Tars, liquid, including road asphalt and oils, bitumen and cut backs 1999... 

The primer, defined in the first part of this paper as a cut-back of the same or a compatible, unfilled, oxidized asphalt dissolved in a high flash petroleum fraction, should be scrubbed into the concrete surface with a broom or stiff brush (roller or spray application is not recommended) and allowed to dry to permit the solvent to evaporate. This usually takes about 3 to 4 hours, at which time the odor of the solvent will have become faint. This leaves a black deposit of the asphalt in the pores and on the surface of the concrete. If the black color fades away, or becomes gray, the concrete is porous, and another coat of primer is necessary. Repeat until the surface remains black. 

Cut-back bitumen constitutes bitumen whose viscosity has been reduced by the addition of a relatively volatile flux. In case the volatile flux is derived from petroleum, the material is called petroleum cut-back bitumen. Typical petroleum-derived fluxes used are white spirit and kerosene. Petroleum cut-back bitumens are almost exclusively used, and, for simplicity, they are called cut-back bitumens (or asphalts). 

The cohesion of stabilised binder from polymer-modified cut-back and fluxed bituminous binders, which are used for surface dressings, shall be determined in accordance with CEN EN 13588 (2008). For binders used in asphalt mixes, the test methods given in either CEN EN 13587 (2010) or CEN EN 13589 (2008) rosy be used. For binders used in other applications,any one of the three methods listed above, CEN EN 13587 (2010), CEN EN 13589 (2008) or CEN EN 13588 (2008), msy be used. 

Petroleum cut-back asphalts apart from curing rate are graded with reference to their minimum kinematic viscosity at 60°C. 

Table 3.11 Requirements for cut-back asphalt - medium-curing type...

According to the abovementioned data, the usage of petroleum cut-back bitumens, as well as the fluxed bitumens, has been limited, and in some countries, their usage has been prohibited (Asphalt Institute MS-19 Chipperfield and Leonard 1976 Nikolaides and Oikonomou 1987 Transportation Research Board No. 30 1975). 

Modified bitumen can be used in the whole range of bitumen works, namely, for producing bituminous mixtures (hot to cold), in surface dressings, surface sealing, water insulation and so on. Modified bitumens may be employed directly or in the form of cut-backs or emulsions, or blended with, for example, natural asphalt. 

Cold asphalts are bituminous mixtures in which the binder material is bituminous emulsion. This chapter does not cover cold asphalts produced with cut-back or flushed bitumen. 

The only effective treatment for corrugations and shoving is to remove the deficient asphalt from the whole affected area and replace it with well-designed and properly produced asphalt, avoiding the use of cut-back for tack coating. 

---