Influence of environmental parameters on the processes of occurrence and development of defects in bridge structures

Abstract

Environment influence in the form of precipitation, temperature variations, seasonal freeze-thaw cycles and human activity lead to the appearance of damages (defects) on the surface of reinforced concrete structures of buildings. As studies show, untimely performance of works on maintenance of objects and subsequent elimination of defects during operation increases the probability of premature destruction of the structure many times.The article analyzes and classifies the main defects and damages of elements and structures of transport infrastructure structures depending on the place of formation on the structures, the nature of distribution, the impact on the main technical and economic indicators and parameters. Thereasons of their appearance and subsequent influence on durability, traffic safety and load-carrying capacity of the structure are revealed. Based on the results of the inspection of the technical condition of the building structures of individual bridge structures, laboratory tests were performed to determine the physical condition of concrete by taking samples from the elements at the locations of identified damages and defects. The content of calcium ions, chlorides, pH, as well as the degree of carbonization were determined in the concrete samples under investigation, and the results were compared within the bridge structures under consideration and with the data of normative and technical literature. To obtain an objective picture, laboratory tests of water samples from the bridges crossing obstacles (rivers) were carried out. The influence of the geographical location of thestructures on the condition of materials of building structures, the degree of their damage and operating conditions was assessed. The existing approaches to predicting the durability of transport infrastructure structures were analyzed separately –the reliability of the results obtained taking into account the technical condition of structures (damage and defects of materials), the quality of work performed during the construction of the structure and others.