stress–strain state

The paper presents the results of an experimental investigation into the stress–strain state of an reinforced concrete (RC) slab subjected to two concentrated forces. The relevance of the study is driven by the need to refine the deformation characteristics of thin slabs experiencing large deflections. The aim of the research is to analyse the evolution of strains in concrete and reinforcement at various loading stages up to failure. The digital image correlation method was employed to measure displacements and strains.

This study presents a methodology for assessing the technical condition of district heating pipelines under high wear, variable thermal loads, and limited modernization resources. Emphasis is placed on installation defects, cyclic temperature and pressure fluctuations, and corrosion-induced degradation. A case study of a return water pipeline in Kremenchuk, featuring a 3° installation misalignment and 10 cm flange displacement, demonstrated stresses of 220–250 MPa, exceeding the steel’s yield strength in critical zones.