Study of the durability of reinforced concrete structures of engineering buildings

Abstract

The degradation process of the long-operated facilities, which include the reinforced concrete structures of engineering buildings, in particular the waterworks based on concrete structures, are characterized by physical and moral degradation processes. The physical degradation is caused by material wear and destruction as well as aging of concrete structures. As for the moral degradation, it is only 2 to 3% for waterworks. The durability of technical structures was assessed by testing the strength of concrete elements of hydraulic structures. The strength tests were carried out on the elements located below the ground surface level, which are in direct contact with moist environment. The tests were carried out using a standard Kashkarov hammer. To ensure and obtain the reliable findings, the trials were conducted in the upper and lower zones of elements with 10 prints in each. Each test series was verified for its affiliation to a sample by removal of abnormal research findings and determination of the required number of prints in the research. Based on research findings, the graph of the elements strength dependence on time was plotted. It was found that the strength of concrete hydraulic structures varies between 35 MPa and 44 MPa. The strength of concrete structures, the actual life of which is 31 years, while the standard life is 20 years, fell by only 10%, while the designed strength margin is 40%.