Experimentally investigation of effects on the performance of jet grout columns with naphthalene sulphonate based construction chemicals

As a result of the growing industry and increasing population in the world and in our country, it has become necessary to build the necessary structure in all kinds of ground conditions. Therefore, ground improvement techniques have gained more significance than existing properties of the ground in case of site investigation. The continuous developments in geotechnical have been conducted to enhance strength capacity, elastic modulus and load carrying capacity of the soil as well as decrease permeability and liquidation of the soil. The code practice covering jet grout injection technique is yet to quantify. Therefore, this study critically investigated the effects of naphthalene-sulphate based chemicals on jet grout columns. Sixteen jet grout columns with the different water-to-cement ratio as well as different admixtures were cast in the laboratory. Naphthalene-sulphate based admixture instigated the increase in plasticity of the mix and injection process was successfully achieved with a water-to-cement ratio of 0.6, compared with injection process consisting of a water-to-cement ratio of either 1 or 1.5. Columns were removed from corresponding soil samples 28 days after casting and dimensional analysis was carried out on the columns. The adequate number of samples were taken from homogenous parts of the columns to determine strength values. The experimental results suggested the same water-to-cement ratio with admixture in the specimens caused the increase in column dimensions (diameter and height). However, usage of admixture instigated the increase in injection mortar and amount of sand grains as well as void ratio, and mitigated ultimate load carrying capacity of the columns.