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Experiments were performed to evaluate the mechanical response of adhesive anchors embedded in high performance concrete (HPC). The variables include compressive strength of the concrete, addition of steel microfibers, load direction, embedment depth and edge distance of anchors. These two latter parameters influence the results both in terms of strength and ductility, while fibers strongly affect only the post-peak behavior and the failure pattern. The influence of the selected factors on the results, in terms of strength, stiffness, failure mode and failure pattern, is discussed. Finally, by considering tensile test results, an approach to evaluate the true bond strength is proposed. Shear test results are compared with standard equations to determine their suitability in predicting the behavior in HPC. The results showed that fiber reinforced concrete is a practical alternative\ud when edge distance, short anchor spacing or thin depth member is required. In addition, it seems that unconfined tests in HPC allow to better evaluate the bond strength of the bonding agent

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Typical applications for post-installed rebar connections consist in overlapping joints with existing reinforcement or anchoring of the reinforcement at a slab or beam support. At cold state it may be shown by testing that a post-installed rebar system can develop the same bond resistance with the same safety margin as cast-in-place rebar. Consequently, anchorage length and lap length for post-installed rebars can be calculated as for cast-in-place according to the Eurocode 2 provisions. However, when subjected to temperature, the decay in bond properties for post-installed systems is significantly more dramatic than for cast-in-place rebars. The paper presents the result of an experimental campaign carried out on a post-installed connection using a vinylester polymer, investigating the effects on the bond strength both of the temperature and of different testing conditions. Finally, design criteria are provided and applied to a typical case study consisting in a post-installed solid slab.

Detailed experimental observations and numerical simulations are presented for the evaluation of residual properties of high-strength concrete specimens after exposure to high temperatures. Heated and nonheated notched four-point bending specimens were tested at ambient conditions approximately 1 month after exposure to the high temperature. Residual strength and post-peak response were monitored using a closed-loop load frame, and the fracture process zone was observed using Electronic Speckle Interferometry. The symmetric over-nonlocal formulation of a microplane model was used for interpreting the experimental investigation. The size-effect results were used to identify the true tensile strength and the initial fracture energy corresponding to the peak and the initial post-peak slope of a linear cohesive crack law. This study reveals that the material ductility increases with the thermal damage, which is explained by the increase of the fracture process zone size and the characteristic length.