LAUSR

Effect of thermoset type polymeric additives on load-bearing capacities of grouted rock bolts was investigated with both laboratory and site studies. For the specimen preparation, two different silicone-based polymeric materials were added with different amounts in the cement and water mixes. Additionally, cement grouts without the polymeric additive were also used to compare results obtained from different grout usage cases. The additives are in the liquid phase while adding into the fresh cement mix and start to solidify due to the polymerization after being mixed in the grout material. Support performances of various grouted rock bolt specimens were tested under axial and shear loading conditions. According to the results of this study, use of the polymeric additives with an amount of 3.5% by weight in total mix significantly improves the ductility in support reactions of grouted bolts and increases the energy absorption capacity by high rates over 50%.