Carbonation of soil cement mixture is defined as the reaction of atmospheric CO2 with hydration products in the presence of pore water. This reaction yields CaCO3 and causes degradation of cemented layers which in turn reduces the strength and durability of soil cement. This deleterious reaction in the pavement can be accelerated by an increase in CO2 concentration. In this paper, a detailed technical assessment has been performed to evaluate the effects of the organic content of soil on the rate of carbonation. The results from the study will help to better understand the root causes of such deleterious reactions.