Laboratory study of an injected granular soil with polymer grouts

Soil or rock mass with low strength or high permeability may not be appropriate for an excavation project or for use as a structural support. These soils or rock mass can cause severe damages to overlying structures, because of their considerable distress. Therefore, a suitable ground improvement technique is needed for deep excavations in order to confront these problems. The increase in strength and durability, as well as the reduction in compressibility and porosity are the main aims of a ground improvement technique. Grouting is the commonly used method to meet the above requirements. In recent years, various types of water soluble polymers are used as additives in cement grouts to improve the soil properties. The main objective of this laboratory project was to investigate the use of such materials for the improvement of physical and mechanical properties of a granular soil. Grouts were prepared by using cement, clay, water in different percentages along with an amount of acrylic resin or methyl methacrylate co-polymer emulsion. These two substances are the most widely used non-toxic additives in concrete structures and applications due to their significant contribution to the improvement of physical and mechanical properties of mortars or concretes. Grouting experiments were performed through 10-cm diameter and 150-cm height columns, filled with granular soil with particle size distribution of 2 - 12.7 mm. The experimental results reveal that the addition of latexes in thick pure cement grouts improves substantially the physical and mechanical properties of the injected soil.