Pull-Out Tests and Numerical Simulations of Bonded Threaded Anchors in Concrete Blocks with Thermal Insulation Layer

What is it about?

The article presents the results of pull-out tests and computer simulations of three-layer concrete block elements with an internal insulation layer made of foamed polystyrene. The concrete block elements are fragments of an external layer of a wall of traditional large-panel buildings. The purpose of the tests was to obtain the ultimate destructive force of a connection. It is not desirable to check the carrying capacity of such anchorages in a residential building. E.g., pull-out tests are the destructive ones and can cause permanent damage to a wall. The durability of a connection surface between the textured layer and other ones strictly depends on the durability of near anchoring. The concrete block elements were designed using C 12/15 class concrete in accordance with Eurocode 2. The connection of a threaded steel anchor with concrete was made using “R-KER vinyl ester bonded anchor” resin with an adhesion stress value of 7 N/mm2. The steel anchor is a threaded rod with a diameter of Ø 12 mm made of steel grade 5.8. The computer simulations are a conceptual proposal for modeling layered block elements in systems and connections not used so far. A primary aim of them was a validation of the experimental tests and a first attempt to the theoretical assessment of the single adhesive anchor strength. In the numerical modeling, it was necessary to accurately model contact in joints, like resin with concrete or resin with steel anchor. The assumed thickness of the connection area is 2 mm in the computer simulations (theoretical space between a concrete and an anchor outer surface in a connection). The threaded part of rods is taken into account in FEM calculations.

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