Optimization of Constructive and Organizational and Technological Parameters of Bridge Structure Renovation

The results of the study on the optimization of structural and technological solutions in the restoration of bridge structures are presented. Reinforced concrete structures damaged by corrosion of concrete and reinforcement, delamination, leaching and concrete soaking are partially replaced and strengthened. The proposed design of a monolithic overlay slab allows for the reinforcement of the prefabricated span structure and the removal of intermediate expansion joints, which are a weak point of the bridge deck. The solution to arrange cavities in the slab is rational, which reduces the material consumption of the technological process. The effectiveness is confirmed by data from the comparison of bending moments from constant loads in the extreme beams of slab span structures. A number of criteria have been identified by which the feasibility of performing an overlay slab can be assessed. For spans of more than 18 m, additional forces in the span structure from the own weight of the overlay slab and sidewalks (especially in the extreme beams for the beam structure) significantly reduce the reinforcement effect (the larger the span, the less effective). In continuous span structures, there is no need to remove intermediate expansion joints (they are absent). In continuous span structures, the maximum tensile forces arise in the supporting sections, in which the overlay slab is made; this leads to a significant change in the structural scheme of the spans and, as a result, significantly higher costs for reinforcing the span structure. With the advent of modern waterproofing systems (epoxy compositions, methyl acrylate compounds, etc.), which have a significantly longer service life and reliability compared to bitumen waterproofing systems, the effect of blocking water access from the bridge deck to the lower structures by the body of the monolithic overlay slab has lost its relevance.