OPTIMIZATION OF THE PARAMETERS OF REPAIR AND CONSTRUCTION WORKS DURING THE RESTORATION OF A REINFORCED CONCRETE PIPELINE

Abstract. Reinforced concrete bridge structures have been widely erected in various countries since the middle of the 20th century. For such structures, problems of reduced durability due to damage from various influences are often found. Degradation mechanisms of structures significantly reduce the duration of safe operation. Rehabilitation and restoration of reinforced concrete of bridges and overpasses requires rational solutions for predicting the long-term strength of structures. Economic indicators of restoration are consistent with the duration of works, which is important for large cities. The presented studies reflect the optimization of structural and technological solutions during the capital repair of the overpass in Kyiv. The surveys carried out at the stage of project preparation did not give a complete reflection of the technical condition of the building for the preparation of final repair decisions, full information was obtained only after partial dismantling of the damaged structures. The support posts had corrosion of concrete and reinforcement, vertical stress cracks, delamination of concrete layers, leaching and locking of concrete. It is proposed to preserve part of the damaged structures of reinforced concrete supports with their strengthening. Removal of damaged concrete and exposure of working fittings, arrangement of additional reinforcing frame, external concreting of racks with a self-compacting mixture in fixed formwork made of metal pipes are provided for. The technology of restoration and reinforcement of the rack made it possible to preserve the existing reinforcement of the rack and its anchoring in the body of the bored pile. The removal of part of the damaged concrete was carried out in accordance with the sequence and volume of dismantling works. The reduction in the duration of restoration works, which is crucial in the conditions of intensive car traffic in the city, took place by 17%. The parameters of the bearing capacity and the design service life of the restored rack have been brought to the level of the parameters of the new design.