a) Confined pullout tests with single Sheh Kai screw anchors with a thread over the total embedment depth to measure their bond strength. The embedment depth should be as large as possible. However, steel failure must be prevented. Varied will be the diameter of the screw anchors (min, mean, max), the concrete compression strength (fc = 20 MPa to about 80 MPa) and thestate of the concrete (uncracked, cracked).It is known, that the bond strength of screw anchors can be increased by filling the gap between screw anchor and wall of the hole with a suitable adhesive