Selected Answers

From Joe Miller of NextGen Green Building Products, Inc. dba Direct2Contractors.com on May 28, 2015:
There are liquid penetrating crystalline sealers a ...read more There are liquid penetrating crystalline sealers available for concrete (and asphalt) floors and pavements. These liquids penetrate into the capillaries and voids and form crystals that expand when water or moisture vapor are present. Depending on the type of oils in the concrete, these liquid penetrants may also be considered for some projects.

From Warren Brand of Chicago Corrosion Group on May 21, 2015:
All great answers. We were working on a floor sum ...read more All great answers. We were working on a floor sump many, many years ago that had been saturated with methylene chloride or some other nasty solvent. It hadn't damaged the concrete, but, instead, had entered into the ground water. Whenever it rained, a "sniffer" alarm would sound (the sump was in an intrinsically safe tank room), leading to emergency action at the facility because they thought a tank had leaked. We had to figure out how to line a concrete sump that was saturated with materials designed to dissolve coatings. We heated the concrete to about 140 F and applied a heated novalac epoxy, with the idea of sealing in the solvent so quickly that the solvent would not have time to reappear at the surface and interfere with adhesion. With oil-saturated concrete, steam or hot water scrubbing with TSP repeatedly and using the right penetrating materials should do the trick.

From Joe Miller of NextGen Green Building Products, Inc. dba Direct2Contractors.com on May 19, 2015:
 In addition to massive cost savings of using ...read more  In addition to massive cost savings of using minimal surface preparation of concrete contaminated with oils (or other substances), the return to service can be shortened massively as well with interlocking floor tiles. In some projects such as machine shops or commercial kitchens, the new interlocking floor tiles can often be used  the same or the next day. And there is no cleaning water to dispose of, either.

From Larry Muzia of Exceletech LLC on May 18, 2015:
Oils will penetrate into the capillaries of the co ...read more Oils will penetrate into the capillaries of the concrete. Typically, the lighter the oil, the deeper the penetration. Using an emulsifier and hot water with mechanical scrubbing is the first step, followed by immediate shop vac to suck up the solution. Repeat the process and perform the water break test to see if the concrete will now absorb the droplets of water. If the water beads up, there is still some form of contaminant present. Remember if water will not penetrate the open porosity of the concrete, it is likely that neither will a liquid resin. Some epoxy primers are more tolerant of oils in the capillaries. (Remember Mobil's V Pok?) The cleaning process can usually achieve contaminant-free concrete at the substrate surface; however, capillary action can pull the oils back up from deeper down in the substrate, in which case as soon as the concrete is visibly dry, a suitable primer should be applied that can achieve at least a partial cure before the oils can again rise to the top, if they have not been thoroughly removed. This process is not a substitute for removal of the contaminated layer, but is just an alternative method.

From Joe Miller of NextGen Green Building Products, Inc. dba Direct2Contractors.com on May 18, 2015:
Determining the best method almost always means kn ...read more Determining the best method almost always means knowing or finding out more about the project. Simply soaking up the oils with an absorbent may be sufficient if one selects an interlocking floor tile to place over the minimally prepared concrete substrate/floor. Interlocking virgin PVC tiles can resist contact with some oils but maybe not every one, so tests should be conducted to ensure the particular oils can be resisted by the tiles. Oils that rise under the tiles can also be removed later if the tiles are not adhered to each other or the contaminated concrete but rely on gravity to remain in place, perhaps with some minimal attachment at the perimeter of the tile field.