Concrete [: a construction material composed of cement (commonly Portland cement) as well as other cementitious materials such as fly ash and slag cement, aggregate (generally a coarse aggregate made of crushed rocks such as limestone, or granite, plus a fine aggregate such as sand), water, and chemical admixtures] [1].



Calcified water spots on paint and glass and water and concrete spots are pretty much the same chemically; calcium carbonate, with the concrete being cross-linked with water. These contaminates often drip after passing through concrete decking or the roof of multi story parking garages



Whatever application method use using short strokes with light pressure or you may cause deep surface scratches



Correction-

• If the concrete is ‘fresh’ try using detailer’s clay



• Apply 1:1 ratio water with distilled White Vinegar solution, and using a spray bottle, spray that mixture on the spots and let them "soak." Then flood-rinse rinse with water to lessen the need to wipe the surface and repeat as necessary.



• If the ambient temperature water/vinegar mix does not work, warm (100-120 degrees) 100% distilled White Vinegar, saturate a clean kitchen sponge with pure vinegar and hold the sponge over the concrete spots for a few minutes



• If the above do not remove them try equal parts distilled water, isopropyl alcohol and distilled white vinegar. The acid in the vinegar will help etch and dissolve the concrete.



• Rinse the area thoroughly with water after the vinegar and then reapply wax or sealant to that area.



Back-Set by Romix - is a paint safe acid alternative with no fumes or odours, molecularly breaks down the ionic bond in Portland cement, completely dissolving and releasing the hardened cement from any surface it is adhered to. Chemically speaking, Back-Set converts the positive ions in the hardened matrix into negative ions, which dissolves the cement into mud that can be rinsed away. Because it works chemically, rather than mechanically, Back-Set may be used to remove cured concrete, mortar, grout, and stucco from virtually any surface without harm. Always apply to a dry surface area