Experimental investigation of behaviour and failure modes of chemical anchorages bonded to concrete

In this study, the effect of using different adhesive types, anchorage diameters and embedment depth on the tensile strength of the anchors were evaluated. In the experimental work, concrete blocks on which the anchor was embedded were unreinforced and had a compressive strength of 25 MPa. The ribbed construction iron bars with 12, 16, 20 and 24 mm diameter were selected to be used as anchors. The depth of embedding is determined to be 5, 10, 15 and 20 times the diameter of the used anchors. The holes, to which the anchors were embedded, were 4 mm larger than the anchor's diameter. 10 different types of chemical adhesives were used in the study. These adhesives are based on 4 epoxy, 3 polyster, 2 epoxy acrylics and 1 vinylester. By using the load-displacement graphs obtained from this study, axial load capacity, failure modes, initial stiffness, displacement ductility ratios and energy dissipation capacities were calculated and important conclusions were obtained from discussing the experimental results regarding the general performances of anchors. Also, capacity and design strength of anchors were calculated according to ACI 318 (2008). As a result, the effect of the chemical adhesive usage on the anchors performance was evident in the anchors with diameters of 16, 20 and 24 mm while, at small diameters, the effect wasn't clear also the best durability was obtained when using epoxy-based adhesives, and the ideal embedding depth was 16 mm for 10Ф anchors and 20 and 24 mm for 15-20Ф anchors.