Microstructure of one-dimensionally consolidated cohesive soil with different pHs

In order to clarify the influence of pH on soil structures of one dimensionally consolidated cohesive soils, consolidation tests were performed on six soil samples in which pH values were artificially changed by adding sulfuric acid or sodium hydroxide solutions. A scanning electric microscope made observation of soil structures. It was shown that the soil structures formed by the consolidation changed with pH values and the kind of soil sample. Although acid soil samples formed flocculent structures, alkaline soil samples formed oriented structures. This may be due to the difference of electric charge of soil particles with different pHs.

pH

cohesive soil

soil-structure

one dimensionally consolidation

SEM photograph