Laboratory evaluation of cement-based grouts and grouted rock anchors

Abstract The paper reports the findings of a laboratory study on six different types of cement-based grouts and two types of steel rock anchors. The physical and mechanical characteristics of cement grouts employing silica fume, aluminium powder, superplasticizer or sand are compared with those of conventional cement grouts. Pullout tests of grouted, 7-strand steel cable and solid steel thereadbar were conducted under similar conditions for different grouts and embedment lengths. From the results obtained, an empirical equation is derived for the estimation of anchor pullout resistance for a given embedment length. A simple trilinear constitutive model for shear bond stress-slip relation at the anchor-grout interface is proposed and discussed.