Failure Structure of Red-Soils Modified by Fiber-Cement-Stabilized Method

In this study, the fiber-cement-stabilized method which we have already developed was applied to the red-soils in order to improve them. The specimens were made by using the modified soils and the unconfined compression tests were carried out to obtain the strength properties of the modified red-soils. It was confirmed that the modified red-soils have high strength and high failure strains compared to the normal red-soils and cement-stabilized red-soils produced by the conventional method. Furthermore, it was found through drying and wetting tests that modified red-soils have high durability for drying and wetting. In order to consider the failure mechanism of the soils, the internal structure of fiber-cement-stabilized red-soils and cement-stabilized red-soils was studied by using X-ray CT equipment. A clear failure plane was observed in the cement-stabilized red-soils and not in the fiber-cement-stabilized red-soils. The failure structure of the latter soils was complex because the fibers and soil particles intertwined complicatedly. It can be considered that this complicated structure strengthens the connective forces between soil particles and restrains the generation of cracks in the drying process. Therefore, it is inferred that the soil erosion will be much reduced if the red-soils are improved by fiber-cement-stabilized method.