Brittle-Fracture Resistance of the Metal of Hyperboloid Gridshell Shukhov Tower

We determine the impact toughness and study the fractographic characteristics of the fracture surfaces of the old and repair steels (produced in 1906 and 1944, respectively) of the hyperboloid gridshell Shukhov water tower in Mykolaiv, some elements of which were replaced after the Second World War. We explain much lower fracture toughnesses of both steels as compared with their contemporary analogs not only by the principal changes in the technology of metallurgical processes for the last century but also by the degradation of metal after long-term operation. It is shown that the plasticity margin of the old steel is lower than the plasticity margin of the repair steel both according to the results of impact tests and according to the fractographic features of fracture.