RC silos experiences several failures for many reasons (loads during loading/unloading storage material, foundation failures, failures due to low durability etc). So, from these failures, several design issues rising. Current design codes deal with most of them (Eurocodes and USA codes) but how old concrete silos can be strengthened/repaired? With external prestressing, with FRPs, with concrete repair methods (like EN1504 etc), strengthening of foundation etc.