Triaxial behaviour of a cemented sand reinforced with Kenaf fibres

In this study, the effect of Kenaf fibre and cement on the mechanical behaviour of Babolsar sand was investigated by consolidated drained triaxial compression tests. Kenaf fibres with a length of 10mm and a diameter of 1.0mm were added to sand and sand-cement mixtures at a weight ratio of 0.0%, 0.3% and 0.6%. The cement contents were 0%, 3% 6% (dry weight) of the sand and specimens were cured for 7 days. The samples were prepared at a relative density of 70%. Triaxial compression tests were carried out at confining pressure of 50, 100 and 200kPa. The stress-strain and volume change behaviour (measured at 0.1% axial strain), maximum dilation angle, maximum strength, failure envelope brittleness index and stiffness of the samples were described. According to the results, the addition of Kenaf fibres to sand and cement-stabilised sand increased the maximum deviatoric stress by 46% and axial strain at failure point by 400%. The inclusion of Kenaf fibres did not affect the ultimate strength of the cemented sand. Dilation was significantly reduced by the addition of Kenaf fibres (about 11 degrees). The stiffness of cemented samples was reduced (about 40%-180%) with increasing the content of Kenaf fibres. The percentage reduction in the stiffness corresponding to 0.3% content was 150%.