Effects of Salinity and Curing Time on Compression Behavior of Fly Ash Stabilized Marine Clay

This study involves an experimental examination of compression behaviors of fly ash stabilized marine clay cured at different times concerning the influences of pore water salinity. A set of laboratory one-dimensional compression tests was conducted on soft Lianyungang marine clay specimens with various pore water salinities and stabilized with fly ash. Test results indicated that both salinity and curing time influenced the compression characteristic of fly ash stabilized clay. The presence of fly ash obviously reduced the compressibility of the untreated marine clay sample. The semi-logarithmic compression curve of untreated pure soil was a straight line, whereas fly ash stabilized clay samples exhibited the pattern of two straight lines. All the fly ash stabilized soil specimens were well represented by two straight lines in the bilogarithmic coordinate, making it convenient to determine the compression yield stress. The compression index at the pre-yield stage was not susceptible to the variation in the salinity and curing period, whereas at the post-yield stage it exhibited a downward tendency as salinity and curing time increased. The value of yield stress for stabilized marine clay specimen exhibited a downward tendency with increasing salinity, whereas it increased significantly within 7 days and tended to level off with the elapsed curing time. The adverse effect of salinity and the positive influence of curing time on yield stress should be considered in engineering applications.