Bond Behaviour between GRP Reinforcing Bars and High Performance Aerogel Concrete

The bond behavior between reinforcing bars and concrete has a significant influence on the overall load-bearing behavior as well as the serviceability of reinforced concrete components. Extensive investigations have been carried out in the past for glass fiber reinforced plastics (GRP) in connection with normal concrete (NC). It has been shown that the bond behavior of GRP reinforcement is significantly determined both by the surrounding concrete and by the product-specific properties (geometry, materials) of the reinforcement bars. For the production of reinforced components made of high-performance aerogel concrete (HPAC), for which GRP reinforcement elements should preferably be used due to their low thermal conductivity, no studies have been carried out yet. Since it is not possible to simply extrapolate the bond behavior of GRP reinforcement with normal concrete to other types of concrete, 48 pull-out tests were carried out in the investigations presented below to determine the bond behavior. For comparison with the results from the current state of research, the bond behavior of GRP reinforcement in NC was also determined by means of 24 additional pull-out tests. Based on the results, analytical bond stress-slip models were derived for both HPAC and NC. Subsequently, these bond stress-slip relationships were integrated into a FE model and compared with the results of the experimental investigations.