Study of Fibre-Clay Interface Behaviour and Reinforcing Mechanism

The use of fibres in a random orientation within weak/problematic soils is one of the techniques for their improvement. In the recent past, some studies on fibre inclusion in soils at macro-level have been reported. However, the interaction between fibres and soil particles is still not very clear. In the present study, an attempt has been made to explain the response of an individual fibre when the fibre-reinforced specimen is subjected to shear. The comparative analysis between cement-coated and uncoated fibre was done to measure the change in interfacial shear strength of fibre and clay. The effect of different initial orientations of fibre was evaluated by performing the direct shear tests. As the placement of fibre at any specific orientation in compacted clay specimen is practically a very difficult task, the special equipment has been designed to prepare a fibre-clay specimen where a single fibre can be placed at any predefined orientation in compacted clay. The test result shows that the fibre-clay matrix develops high shearing resistance if fibre is oriented near to the horizontal surface. In comparison to the uncoated fibre, due to the development of cementitious bond, the clay specimen reinforced with cement-coated fibre achieves much higher interfacial strength.