Calculation of the Constructive Nonlinearity of Ribbed Reinforced Concrete Slabs of Self-Stressed Covering Panels

Precast reinforced concrete constructions meet the requirements of industrialization, high manufacturability, and cost-effectiveness at a reasonably high level. The ribs in constructions perform load-bearing functions, and the slab part performs enclosing functions. Often before the installation of such structures at a construction site, they are mounted from assembly elements. The overall dimensions of the elements are limited by transportation requirements. During such an aggregated mounting, the assembly units work according to a calculation scheme that differs from an operational scheme. The structural nonlinearity of ribbed reinforced concrete slabs during transportation, mounting, and installation, and the operation of a combined spatial covering panel were investigated in this paper. The effects were identified, and a rational design of nodes connecting the individual prefabricated units into a spatial structure was developed. With the help of these nodes, it is possible to create unloading support moments, which will reduce the internal forces in the design cross-sections. The effects of changes in the width of the reinforced concrete slab shelves on the internal forces of the load-bearing ribs of a wall and a roof panel were investigated

Thermophysical aspects of reconstruction of cold roof spaces

The results of theoretical studies of thermal modernization of cold roof floor. The designs of overlap of long-life roofs of public buildings were considered. Overlap of these buildings are made by wooden or concrete beams and made of concrete slabs with upward edges. The problems of thermal modernization of these designs are consideration of the impact of heat-conducting inclusions on the resistance to heat. The heat-conducting inclusions of constructions are beams and vertical edges of the slabs. The results of calculations of the temperature fields were used for the analysis. The research was carried for the two temperature zones which Ukraine’s territory is divided into. The analysis of thermal protection level of structures overlap was made. The magnitude of the impact of heat-conducting inclusions on resistance to heat after thermal modernization of cold roof floor was observed. The analysis showed that the thermal protection properties of structures less than standard, therefore the insulation of areas with heat-conducting inclusions is required. The options of insulation of these areas were considered. The optimal insulation options with the least amount of additional insulation over the heat conductive areas were selected