Paper Title
Pull-Out Test of Grouted Rock Bolt as Affected by Loading Rate and Curing Time

This study investigated the effects of pull-out rate and curing time on the ultimate load capacity of grouted rock bolts. The laboratory tests include the uniaxial compression test on grouting material and the pull-out test on rock bolts. The compressive strength of grouted cement for curing periods of 3, 7, 14, 21, and 28 days equals 26, 32, 35, 37, and 41 MPa, respectively. The pull-out tests were conducted on the specimens under four different curing periods (7, 14, 21, and 28 days) and pull-out rates (0.1, 0.01, 0.001, and 0.0001 mm/sec) following the ASTM Standard practice. The results indicate that the increasing curing time leads to an increase in pull-out load and displacement, while the effect of loading rate makes for an increased pull-out load but a decreasing displacement. The mathematical equation for the ultimate pull-out load and displacement is presented as a function of loading rate and curing time with correlation coefficients of 0.993 and 0.998, respectively. Keywords - Pull-Out Test, Effect of Curingtime, Loading Rate, Rock Bolt