Accounting for Shear and Cracks in the Inter-Environment Contact Zone of a Reinforced Concrete Composite Structure

Abstract

Statement of the problem. Modern construction actively uses prefabricated monolithic and composite structures made of various concretes. In this regard, when assessing the parameters of stiffness and crack resistance, it is necessary to take into account the features of their deformation and cracking at various stages of loading, in particular, the compliance between layers of composite concrete during the formation of not only traditional normal and inclined cracks, but also longitudinal cracks in the intermediate contact zone. Results. A new constructive solution of a prefabricated monolithic frame for residential and public buildings made of industrial П- and L-shaped panel elements, which are combined into a prefabricated monolithic structural system during installation, is presented. The results of numerical studies obtained using the finite element method and special techniques for "grouting" finite elements to account for cracks, the effect of shear and the formation of a longitudinal crack in the inter-mediated contact zone between the prefabricated and monolithic parts of the crossbars of the frame structures under consideration, as well as the effect of the deformation effect in cracks formed in the stretched zone of the composite structure of the crossbar on the parameters of limiting states of the second group. Conclusions. It is established that the values of the opening width of normal cracks in the composite structure of a prefabricated monolithic bolt depend not only on the stresses in the stretched reinforcement caused by bending of the bolt, but also on shear deformations in the inter-mediated contact zone of the prefabricated and monolithic elements of the bolt and the presence of a longitudinal crack between these elements. The values of the opening width of normal cracks obtained taking into account these factors are confirmed by comparing the calculation data with the test results of reinforced concrete frames with prefabricated monolithic crossbars of composite cross section.