An investigation of mechanical, physical, and microstructural properties of full-scale soilcrete column in organic and clay soil

Jet grouting methods have recently become one of the soil enhancement technologies utilized to provide strength improvement and solve most problems of weak soils. In this study, a full-scale 1 m diameter and 5 m length soilcrete (SC) (jet grout) column was constructed in the organic soil with a water-to-cement ratio of 1 and 400 bar pressure injections. Besides that, SC column has been constructed with 1m depth in clayey soil regarding different pressure injections (300, 325, 350, 375, 400) bar and different rotations (25, 35, 45) rpm. A mechanical, physical, and microstructural investigation was performed on SC samples taken from six different depths (0.0, 0.5, 1.0, 1.5, 2.0, and 2.5) m and at the same depth at five different locations, including the center for organic soil. For clayey soil, the observation of geomechanical properties of SC was taken according to different pressure, rotation parameters, and different location of specimens in grout column. Following tests are performed on each sample: strength characteristics in all conditions, water absorption, density, porosity, and surface friction between SC-soil samples. Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDX) were performed on selected samples to investigate microstructural variation of SC columns regarding all different parameters. The test results showed that the strength of SC varies with depth that exceeded 48%, and within the same depth, the variation is approximately 20% for organic soil, while for clayey soil, the strength decreased by 38% with increasing the pressure and decreased it (6%) with increasing rotations. Other properties (water absorption, density, porosity) also vary regarding all different parameters for both SC in organic and clayey soil. As well as, the surface friction angle of different types of soil-cement grout gains 42° for organic and its varies between 9°-to-19° for clayey soil. The theoretical part of this study is to predict the diameter of SC in both types of soils