Effects Of Calcium-based Treatment On Organic Soil Behavior

Abstract

Organic soils are found in many places around the world. Organic soils undergo large secondary settlements depending on the amount of organic matter present in the soil Organic soil is a mixture of finely divided particles of organic matter, in some instances visible fragments of partly decayed vegetable matter and shells are also present in the organic matter. In order to reduce the secondary settlements caused by organic matter, soil is treated with different stabilizing agents. The difficulties associated with organic soils arise when they are treated with cement or lime stabilizers, as organic matter inhibits cementitious reactions responsible for strength gain. There is a need to understand the fundamentals behind the chemical reactions contributing to the changes in geotechnical properties of stabilized organic soil beds. Subsequently, 12 soil samples are obtained from 6 locations. The locations include Abilene, Austin, Beaumont, Bryan (Huntsville and College Station), Corpus Christi fore research. Laboratory experiments were conducted on the control soil and treated samples (lime and cement). These experiments are conducted to measure the properties like vertical free swell strain, linear shrinkage strain and unconfined compressive strength at different intervals. This improvement factor is also affected due to the presence of organic content. Particularly, unconfined compressive strength of some soils decreased after 56 days of treatment. This may be due to the presence of organics and humic acid in the soil. However, a detailed analysis with increased curing time and preparation of artificial samples with known organic content and humic acid may give better insight into the behavior and strength gain properties of soils due to stabilization.