For the economical construction of fatigue loaded structures with textile reinforced concrete (TRC), it is necessary to investigate the fatigue behavior of the materials. Since next to the tensile load-bearing behavior, the bond behavior of a material is crucial as well, the present paper deals with the bond fatigue of TRC with epoxy-impregnated carbon textiles. First, static tests are carried out to determine the sufficient anchorage length of the investigated material combination. Afterwards, the influence of cyclic loading on the necessary anchorage length, deformation, stiffness, and residual strength is investigated. The results of the cyclic tests are summarized in stress-number of cycles to failure (S-N) diagrams. In the end, it can be said that the cyclic loading has no negative impact on the necessary anchorage length. If specimens withstand the cyclic loading, there is no difference between their residual strength and the reference strength. The failure of specimens occurs only at high load levels, provided that the anchorage length is sufficient.

The strengthening of existing reinforced concrete structures (RC) with carbon reinforced concrete (CRC) has a high potential to save resources and to increase the lifespan of the whole strengthened structure immensely. However, when strengthening structures with CRC, in some cases, failure due to concrete cover separation is detected, leading to the fact that the potential of the carbon reinforcement cannot be exploited. The prediction and prevention of this type of failure is the subject of current research. In this paper, a strut-and-tie-model is presented for calculating a critical tensile force leading to failure due to concrete cover separation. Additionally, possible methods to avoid that kind of failure are suggested. One of these is doweling the ends of the strengthening layer. This paper presents the first experiments to test this method, which show that doweling the strengthening layer leads to much higher failure loads compared to a structure without doweling. However, further investigations have to be examined to verify these first results.

Strengthening of existing reinforced concrete (RC) structures by means of externally applied fiber‐reinforced polymer (FRP) reinforcement was and still is an important research topic. CFRP reinforcement is particularly suitable for infrastructure projects where the actual loads have exceeded the predictions made in the past decades and high chloride input due to de‐icing salts is also present. This article presents experimental and theoretical investigations on the structural behavior of RC members strengthened with an externally applied CFRP textile‐reinforced concrete layer under monotonic and cyclic long‐term loading. A precise analysis of the cross‐sectional behavior and the calculation parameters to determine deflections and load‐bearing capacities of the strengthened RC members is conducted. It is shown that the load‐bearing capacity is not influenced by the preceding monotonic or cyclic long‐term loading and despite the many influencing factors, a good agreement between the calculations and experimental data can be achieved.