ABSTRACT
The results of the inspections of hydraulic structures carried out by the Federal Office of Hydraulic Engineering (BAW) have shown that many hydraulic structures require an increased maintenance demand. In several cases, unreinforced tamped concrete hydraulic structures show not only low concrete strengths, but also cyclic opening movement joints and cracks. Considering the upcoming repair measures and taking the different concrete properties of the existing waterway engineering structures into consideration, four “old concrete” classes were created (A1–A4). These concrete substrates are classified depending on their compressive and surface strength (see Table 1).
