If you are calculating the degree of saturation, or you are plotting the density tests on a proctor graph and they plot to the right of the zero air voids curve - indication 100%+ saturation then the specific gravity you are using may be too low. The specific gravity of soils is typically 2.65...
The best info I can give you on discoloration and possible repairs is this link:
http://www.nrmca.org/aboutconcrete/cips/23p.pdf
The NRMCA / PCA Concrete in Practice (CIP) series of publications are a good guide to help narrow down and resolve some of the most common concrete problems...
Dynamic cone penetrometer testing ASTM STP-399(EB) is used on piedmont soils (fine grain soils)as a construction control test when boring penetration data is known.
The test is performed by marking off 3 - 1.5" increments and counting the number of drops/increment of the 10lb weight it takes...