depict the stressestrain curves for the cementeclay improved by fibers and fiber bundles with the variation of cement content, fiber content and length. As shown in Fig. 6, specimens with cement content of 2% performed much more ductile when others reached their peak strength at the strain 1.5%. It is suggested
that both types of fiber additives assisted with ductility of improved clay with low cement content, which can be attributed to the bonds between soil particles provided by fiber reinforcement. However, the cementation effect was an influencing factor on the ductility of the improved clay when the cement content increased. Figs. 7 and 8
give the stressestrain curves for the specimens with the optimal cement content 8%. All these specimens reached their maximum axial stress at the strain of around 1.5%, regardless of the fiber type, fiber content and fiber length.