THE INFLUENCE OF TEMPERATURE ACTIONS ON THE CRACK RESISTANCE OF LOAD-BEARING STRUCTURES IN A CAST-IN-SITU BUILDING DURING CONSTRUCTION

This study empirically assesses temperature effects on load-bearing systems using field data from an ongoing multifunctional complex featuring cast-in-situ reinforced concrete framing. The calculation-analytical method was employed for design justification, along with mathematical modeling using the LIRA 10.12 software. The results revealed that the strength utilization factor, considering the design reinforcement, exceeded 100% by up to 200% in certain sections of the 2nd underground floor slab, and ranged from 105% to 200% in sections of the 1st underground floor slab. Based on the results of the research, the following conclusions were drawn: cracks in the load-bearing structures of floor slabs and external load-bearing walls of the -2nd and -1st underground floors occurred due to the insufficiency of the calculated reinforcement for the perception of all types of impacts, including temperature; the main reason for the formation of cracks is the absence of expansion joints in the design document of load-bearing structures of the -2nd and -1st floors. According to the research findings the following recommendations are given: when designing cast-in-situ reinforced concrete frame buildings it is necessary to perform a temperature calculation; in case of failure to perform the calculation, it is necessary to arrange expansion joints per the code recommendations; the use of expansion joints in design can be avoided only with appropriate justification.