|
|
|
| Experimental study on mechanical properties of red Pisha-sandstone cement soil under freeze-thaw cycles |
| GENG Kaiqiang, LI Xiaoli* |
| College of Water Conservancy and Civil Engineering, Inner Mongolia Agricultural University, Hohhot, Inner Mongolia 010018, China |
|
|
|
|
Abstract In order to realize the potential utilization value of Pisha-sandstone as a natural resource, the effective utilization of Pisha-sandstone is improved. The red Pisha-sandstone in Zhungeer banner of Ordos City is added with different cement contents to produce the Pisha-sandstone cement soil,and the unconsolidated undrained triaxial tests under different cement mixing ratios, confining pressures and freeze-thaw cycles were carried out. The variation regularities of mechanical parameters of Pisha-sandstone cement soil were obtained, and the meso-structure of Pisha-sandstone cement soil was observed through ultra-depth three-dimensional microscope. The results show that the stress-strain curve of Pisha-sandstone cement soil presents a strain softening trend. The cohesive force and internal friction angle increase linearly with the increase of cement content. The internal friction angle of Pisha-sandstone cement soil is less affected by freeze-thaw cycles, while the cohesion is more affected by freeze-thaw cycles. The more cement content, the better the frost resistance, but the more obvious its brittleness. The meso-structure observation further verifies that the freeze-thaw cycle cause a large change in the meso-structure of cement soil with a small amount of addition, and the increased internal voids can be observed. With the increase of cement content, the compactness of cement soil structure is increased, and the frost resistance of cement soil is effectively improved.
|
|
Received: 17 September 2019
|
|
|
|
|
|
|
