Field manufacture of asphalt cutbacks 2

[defg]

Dear Sir,
Currently I'm carrying out priming works on completed crushed stone base(CRR).Due to lack of enough MC-70 on site, the Contractor has requested to blend 80/100 or 150/200 of penetration grade by using kerosene to produce MC-70.Is there any effect compared to the bitumen produced directly from the factory!Pease assist so that I can advise the Contractor accordingly.

 

[25362]

One problem one may see would be safety-related, since the mixing viscosities are generally lower than 200 cSt, requiring temperatures above the flash point of the distillate. H₂S in the vapors could be another item. Also check the local legislation.

 

[reena1957]

Dear defg,
Apart from the problems pointed out by 25362, I feel there is every chance of Asphaltenes becoming an unstable emulsion and precipitating out of the mixture. In other words, there may be phase separation. Better use a high flash high viscosity engine lube oil(may be used lube oil) for this Penetration blending.
Best wishes

 

[25362]

The use of lubes defeats the purpose of the cutbacks for road uses since a low viscosity is not the only aim of the cutter or flux.

It is precisely its volatility that governs its desired "loss", after use, for a gradual return (curing) to the properties of the parent bitumens. Typical uses are: for RC (rapid curing) white spirit, for MC (medium curing) kerosine, SC (slow curing) types use diesel.

Since vaporization of the cutter is sometimes considered objectionable from an environmental viewpoint, cutbacks are mainly used on minor or less heavily trafficked roads, the growing tendency is now toward bitumen emulsions.

 

[reena1957]

Dear 25362,
I was not aware of this. Thanks for the enlightening post with a star.