Behavior of post-installed large-diameter anchors in concrete foundations

• Prototype experiments of post-installed large-diameter anchors are studied.
• The classic failure modes of post-installed large-diameter anchor systems are given.
• Enrich the literature and empirical data on post-installed large-diameter anchors.

The pull-out force for post-installed large-diameter anchors embedded in concrete foundations was investigated. The main aim is to determine the optimum bonding force and ultimate tensile force of the anchor bar. Anchor bars with various diameters were tested, and different embedment depths were used. The results obtained indicate that the pull-out force improved marginally with an increase in the bar diameter. The primary failure modes observed for the large-diameter anchors included steel bar pullout, concrete annulus damage and combined cone damage. Increasing the bar diameter gradually changed the failure mode from steel bar pullout to a combination of cone damage and concrete annulus damage. Finally, grooved bars were found to be more suitable for use in post-installed anchor systems.