Influence of Reconstitution Method on the Behaviors of a Silty Loess

The mechanical behavior of reconstituted soils is affected by various reconstitution methods. Recently, reconstituted loess soils have gained popularity as a construction fill material due to the numerous large-scale land development projects in China’s loess regions. It is therefore necessary to better understand the behavior of reconstituted loess prepared with different methods. In the presented work, loess specimens reconstituted with moist tamping (MT), air pluviation (AP), and slurry (SLY) methods were prepared, and series of oedometer tests, bender element tests, and triaxial tests under various stress levels were performed. It is found that the specimens prepared with the AP method exhibited the most weak and unstable microstructure, while those prepared with SLY method displayed the most strong and stable microstructure. The compression behavior, small strain stiffness, and shearing behavior of loess soil were significantly affected by the initial soil structures induced by the different reconstitution methods, particularly when the mean effective stress is less than 200 kPa. The structure effect only can be erased when the specimens are sheared to the axial strain of at least 30% under the confining pressure exceeding 1,500 kPa. This study highlights the sensitivity of the mechanical behavior of loess to different reconstitution methods, which is valuable to engineering practice in loess area.