Abstract:The influence of mixture ratio of grouting material on the pull-out behaviors of rock cable is obvious,which is one of key parameters for the optimal design of prestressed anchorage systems. Unfortunately,few studies are found about the influence of mixture ratio of grouting material on the pull-out behaviors of rock cable;and there are not sufficient or professional standards established for the special grouting material in prestressed anchorage specifications. Based on many investigations of in-situ projects,eleven cement-based grouting materials with different mixture ratios and related physico-mechanical characteristics are respectively tested;and the laboratory pull-out test has also been carried out to study the influence of mixture ratio of grouting material on the limit bearing capacity and load-displacement behaviors of rock cable. The results of pull-out tests show that mixing appropriate amount of sand into cement-based grouting material could increase the fracture energy,thus enhance the roughness of cementation interface between cable and grouting material,and increase the restraint of cable untwisting expansion. The limit bearing capacity of rock cable,consequently,is remarkably improved. However,it has less effect through decreasing the water-cement ratio to elevate the limit bearing capacity of rock cable. Debonding along the cable-grouting material interface is the dominant failure model of conventional prestressed cable bolt,so great importance should be attached to the failure model in the design of anchorage engineering and revision of technical specification for prestressed anchors in the future.