An elastic analysis that predicts the pull-out capacity of adhesive anchors

Abstract

Adhesive anchors been widely used in both new construction and repair/retrofit projects because of their rapid curing speed and economy. They are thus especially attractive for use in sustaining aging infrastructure. However, recent accidents have shown that current design procedure may not be safe. Although several failure modes exist in engineering practice, this work focus on the failure due to pullout of an adhesive core. A rational examination of the current elastic model has been conducted, and its limitations are presented. A new elastic model is developed for the future design of adhesive anchors. An axisymmetric problem is studied for an adhesive core bonded to a rigid hole through an adhesive layer. The stress distribution within the adhesive interlayer is derived, and then the load capacity of the anchor can be obtained. Compared with the existing design method, the proposed model provides the elastic fields at both the adhesive core and the adhesive layer, which makes it possible to capture different failure mechanisms. The model's assumptions are then validating using an axisymmetric finite element model. An extension of this work to consider the creep behavior and predict the long term performance of adhesive anchors is underway.