Laboratory Investigation of the Effect of the Cement Treatment of Interface on the Pullout Capacity of Reinforcements

Mechanical specification of the interface of soil and reinforcement is one of the most important parameters of the design and construction of reinforced soil systems. Anchorage length of the reinforcement is determined based on the soil-reinforcement interface parameters. Required long anchorage lengths restricts the application of reinforced soil systems. Improving the mechanical parameters of the soil-reinforcement interface could be used to develop the applications of reinforced soil structures in projects with limited space. In this research, the cement treatment of the interface of the soil and reinforcement was employed to improve the pull-out capacity of the reinforcement and consequently to reduce the anchorage length. The effect of the cement treatment on the pull-out capacity of the reinforcement was studied in the laboratory. Also, the effect of the increased thicknesses of the reinforcements resulted from the cemented layers adhered to the reinforcement surface was investigated. The laboratory tests conducted using specially developed pull-out test device. The tests conducted on high-strengths woven geotextiles with different thicknesses with both pristine and cement treated interfaces. Cement treatment carried out with 1.5 g/cm2 portland cement sprayed on water saturated geotextile. The results of tests conducted on pristine reinforcements with different thicknesses showed that increasing the thicknesses of the reinforcements increase the pull-out capacity. Also, the cement treatment increases the pull-out capacity of reinforcements.