Factors affecting chemical anchor pull-out strength

Most of the existing building stock in our country does not include the conditions stipulated by the current earthquake regulations. It is known that structures that do not have earthquake safety need to be strengthened. There are various methods for strengthening applications. If new elements are added to the carrier system, the most preferred method is to attach the anchors with chemical adhesives. Easy and fast application, high adhesion strengths are the superior properties of chemical anchors. For a safe design, it is important to know the behavior of chemical anchors under tensile, shear and bending forces. In this study, tensile strength of chemical anchors were investigated under different diameter, depth and environment conditions. Anchor rods with a diameter of 12, 16 and 20 mm were planted at depths of 5, 10, 15 and 20 times the diameter under different environment conditions. The cleanliness of the anchor holes, the humidity and temperature are also variable. As a result of pull-out experiments, load-displacement curves, axial load capacities, failure modes, stiffness, displacement ductility ratios and energy absorption capacities of anchors in different diameters, depths and environment conditions were determined. ACI 318 Annex-D's capacity and design strength values for anchors were determined and the safety coefficients were compared with the test results. As a result of the study, it was seen that the strength of the chemical anchors was affected by the cleanliness, humidity and temperature of the holes where the anchors would be planted. It has been determined that there are issues to be considered in order to obtain the desired strength from the anchors.