In this book, the time dependent changes induced in soil-stabilizer matrix are studied using various spectroscopic and microscopic techniques such as X-ray Diffractometry (XRD), Energy Dispersive X-ray Spectrometry (EDAX), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Nuclear Magnetic Resonance spectroscopy (NMR) etc. This highlighted a very important point regarding the chemical composition of reaction products. Based on the results, it was found that in soils comprised mainly of kaolinite mineral, clay alumina was more liable to dissolution and therefore, aluminate hydrate compounds were more likely to be formed in a low and high pH environment. Nonetheless, the coating action of iron oxides was believed to have a detrimental effect on the progression of pozzolanic reactions in lime treated iron-rich kaolinitic soils. This book, therefore, suggests the most significant processes that take part in the formation of cementitious products in chemically treated soils and should be useful for geotechnical engineers and researchers who are interested in understanding the soil-stabilizer interaction at the particle-level.