I.S. Muminov

Annotation:

The article considers the stress-strain state of the slab-column connection in a flat-slab reinforced concrete frame under increasing load. A 3D computational model of the connection was developed at a 1:1 scale using the LIRA-SAPR software package. The analysis was performed taking into account the physical nonlinearity of concrete and reinforcement. Heavy concrete of class B25, longitudinal reinforcement of class A500, and transverse reinforcement of class A240 were adopted as materials, with physical and geometric nonlinearities taken into account. The load was uniformly distributed over the entire slab area and increased stepwise by 1 kN/m² up to a maximum value of 30 kN/m². During the analysis, normal and shear stresses in concrete, the development of local cracking, as well as normal forces N in the reinforcement were analyzed. It was established that the most highly stressed zone is the support region near the column face, where stress concentration is observed. With a further increase in load, the damaged zone gradually expands along the directions of the hidden beams. The obtained results show that  the hidden beams participate in the redistribution of internal forces and affect the behavior of the connection. This makes it possible to assess the specific features of the stress-strain state of the connection under increasing load.

Keywords: beamless frame, slab-column joint, stress-strain state, LIRA-SAPR, physical nonlinearity, hidden beam, crack formation, normal stresses.