new oil/old oil/asphalt

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2,435
Location
Mizzou-land
When I was a kid, the oily spot in an asphalt driveway became indestructable. It seem to be protected from everything. Now, the oily spot in an asphalt driveway is destined for an early grave. Why is that? Is it a base oil thing? Or, are the additives the key?
 
Messages
3,480
Location
Millbrae, CA
asphalt comes from oil refining and oils will disolve or break it down. In the industry concrete is used any where oil/fuel will spill like at a loading rack asphalt is NOT durable where oil/fuel falls. Why you had a oily spot that did not crumble maybe due to the age/compactness/aggrigate used in the driveway. bruce
 
Messages
2,688
Location
Elderly County, Florida
As my dear old Grand-daddy used to say, "like disolves like." I kid you not, he would clean his hands with dirt and they would come clean. For a greasy, nasty engine that he wanted to clean, he would take used motor oil and an old paint brush and "paint" it with the used oil. Let it sit for a while and then turn the garden hose on it. Always came clean. I have to agree with bruce - I've never seen an asphalt driveway that could stand up to oil, grease, gas, diesel, etc.
 
Messages
1,910
Location
Vista, CA
When I was a kid, the neighborhood gas station would dump their used oil on the dirt driveway in back to keep the dust down. It soaked into the ground and dit it's job really well. I guess today, it would not be such a good idea. The dust must be good for us.
 

GMorg

Thread starter
Messages
2,435
Location
Mizzou-land
My thought was that older oil formulations had lighter fractions that would evaporate and leave behind heavier stuff that was akin to asphalt anyway. In addition, I thought that it may oxidize a little easier and form insolubles. So when old oil was combined with dust it would make its own asphalt-like patch. The volatility range of modern oil tends to be narrower. So, less really heavy stuff and less really light stuff. In addition, it seems to clean better anyway. I think newer oil dissolves asphalt better than oil of the '60s and '70s. Maybe my memory is going, but it seems there use to be raised, smooth areas in parking lots where now there are broken, rough, fragmented areas. I am referring to the area in a parking place just below the average oil pan.
 
Messages
661
Location
Bosphoria
I spilled well-worn PS fluid in the asphaltum parking place. It was a three years of shame every time I see that and note the self "I did this mess". Last month I spilled some semi-used AT fluid on concrete and asphaltum. Concrete one dissapeared the next day, and I think asphaltum won't stay like this for months. The higher wax content might be one answer, and how oxidized it was when spilled. I have one additional thougth that what stains long term the unabsorbent surfaces must be the metallic content in the oil. The fine dark heavy metallic dust is hard to be washed out. Same for the coolant. I don't know the chmistry of this one but the more stable paints tend have more metallic content too. For. eg. uv resistant red is one of the less preferred colors in the printing industry if you are to say "ecological packaging".
 
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