petroleum cut-back and fluxed bitumen gen.

[milamia]

Встретилось рядом два названия - petroleum cut-back и fluxed bitumen:

For testing petroleum cut-back and fluxed bitumen for which specific gravity at 25 °C is assumed to be lower than 1, isopropanol (propan-2-ol) with a density of (782,7 ± 0,1 ) kg/m3 at 25 °C shall be used.

Мне кажется, что оба сочетания означают разжиженный нефтяной битум...Подскажите, в чем разница между ними?

[rpsob]

Скорей всего, различие между ними все же есть.
cut-back petr. -"урезанная нефть" - c отогнанными легкими фракциями. Чтобы получить битумы нужно
дополнительно отогнать (ректифицировать) средние фракции.

[milamia]

А далее нашла по тексту: cut-back bitumen и fluxed bitumen, тоже в одном предложении. И как тогда?

[fiammetta]

petroleum - нефтяной
cut-back в примечаниях в мультитране "быстрогустеющий", fluxed - "медленногустеющий". Возможно, разный разжижитель или степень разжиженич

[milamia]

Спасибо!

[fiammetta]

Cut-back bitumen
Cut-backs are bitumen preparations in which the viscosity of the binder has been reduced by the addition of a volatile solvent, normally derived from petroleum. Typically the solvents used are white spirit and kerosene. Cut-back products are typically used for spraying and some mixing applications.
Fluxed bitumen
Fluxed bitumens are bitumen preparation where the viscosity of the binder has been reduced by the addition of relatively non-volatile oils. Typical fluxants include gas oil and vegetable based oils.

[fiammetta]

FLUXED BITUMEN refers to a BITUMEN that was a stiff PENETRATION GRADE but has had its VISCOSITY reduced, i.e. made less viscous, by the addition of a NON VOLATILE oil.
So that we now have a BITUMEN of lower viscosity i.e. lower stiffness.
I repeat, the oil used to FLUX the stiff BITUMEN is NON VOLATILE, it will not evaporate, you have produced a less viscous, less stiff BITUMEN, "more runny", a very un-technical term but I hope it conveys the meaning.
A FLUXED BITUMEN will NOT revert to its original VISCOSITY but remain at the new VISCOSITY you have created by the addition of the FLUX OIL.
A FLUXED BITUMEN is different from a CUTBACK BITUMEN for the above reasons.
A FLUXED BITUMEN will be formulated to remain a penetration grade bitumen, but a softer / less stiff grade suitable for the material and conditions where it is to be used.

A CUTBACK BITUMEN is a BITUMEN that has been blended with a VOLATILE oil, most likely to be kerosene but others are used, so that when the volatiles have evaporated, with time, the BITUMEN will eventually revert to its original VISCOSITY.
Time being the critical factor, it may take many months or even years before the cutback mixture regains the viscosity of the bitumen that was cutback.
Whilst the material remains in the softer condition it will be susceptible to damage from overloading of the material layer.