Development of effective compositions of concrete for the construction of slabs of the roadway of steel concrete span structures

Abstract

Structural concrete spans of various systems and structures with modular and monolithic roadways were used in the construction of bridges. The article presents the results of a survey of such bridge structures at 3 sites: across the Suju River (Grozny), across the Vologda River (Vologodsk), across the Tsna River in the town of Shatsk, Ryazan Region. Defects and damage to the plates of the carriageway are given. It was found that the most dangerous factors affecting the early failure of the roadway steel-reinforced concrete structures, is used to combat glaze and ice sleet aggressive in relation to reinforced concrete sand-salt mixtures. In addition, the lack of durability of structures due to other factors: vulnerability to carbonization processes; lack of reliability of the mounting joints and connections, the heterogeneity of the plate on the transverse and longitudinal bending. An algorithm for determining the parameters of the safe operation of the elements of bridge structures has been compiled; on the basis of the results of the study, the need to solve two urgent problems has been identified: urgent repairs; development and implementation of new solutions for construction and repair. It is shown that in world practice various types of concretes are developed: powder-activated, frame, etc. as well as protective materials – fine polymer concretes. Provides data on the cyclic strength of these materials, as well as the technology of their installation. In the study of the degree of influence of factors of temperature and humidity of the environment on the amount of short-term creep of polymer concrete, the method of experiment planning with the construction of an orthogonal composition plan was used and a methodical model was obtained relating these values. The main stages of the device of the polymer concrete slab instead of the collapsed one are given. The prospects of polymer-concrete coatings produced by frame technology, consisting in the first stage of gluing the aggregate grains with each other in the form of a future product, and the second, filling the voids of the porous frame with a highly mobile polymer composition is shown.