One of the main goals in building construction is to design future reinforced concrete structures that are resistant to unexpected loads. In other words, the structure must be designed to operate reliably and safely. Two key reliability assessment criteria are the ductility of the structure and the “cracking before failure” principle. Known cases of corrosion damage to prestressed concrete are considered. It is proposed to determine the residual load-bearing capacity and safety factor of the cross-section of a prestressed concrete beam using the area of residual prestressed reinforcement due to corrosion damage. Two cases of moment redistribution are considered: from span to support, when the loss occurs in the span, and from support to span, when the loss occurs at the support. To ensure the strength of reinforced concrete beams for statically determinate and indeterminate systems, it is proposed to determine the minimum reinforcement based on their ability to plastically rotate upon loss of prestressed reinforcement.

Representative experimental studies are necessary for the normative substantiation of the controlled parameters of the rolled products. The paper presents the results of experimental studies of the adhesion of reinforcement of the new strength class A550 with concrete. Statistical processing of the results is given. The main ones are defined. The experimentally evaluated specific bond strength indicators, kN/mm, of reinforcing steel d10–36 A550 in concrete classes B30–B40 demonstrated a stable increasing linear dependence on the relative bearing area of the transverse ribs f_R. This requires verification on other cross-sections of the rolled product and its rib parameters. However, it can be stated that with a probability of 0.95, accounting for the actual cross-sectional parameters in the improved method for evaluating the anchorage value of the rolled product will allow, within the scatter of properties even within a single batch, for a justified adjustment of the design bond strength between reinforcement and concrete by up to 15 % for small-diameter rolled products (up to 20 mm) and up to 10 % for larger diameters (20+ mm). For the latter, the rationalization of the normatively required large design anchorage lengths is the most effective and promising.

During operation, building and structural systems may be subjected to various types of accidental actions, creating a risk of complete or partial collapse. This study investigates the stress-strain state of reinforced concrete columns in building frames under emergency conditions.  The stress-strain state of such elements depends on the localization of the initial failure, the presence and stiffness of outrigger structures, the location of shear walls, and the stages of floor structure behavior in an accidental situation.

Experimental data were obtained to study the influence of reinforcement geometric parameters on the stress-strain state of flexural reinforced concrete structures and to consider reinforcement profile parameters as a design parameter. The study resulted in the obtained data on the main physical, mechanical, and deformation properties of reinforced concrete beams, as well as the adhesion of reinforcement with various periodic profiles. These data can be applied in the design of reinforced concrete structures by selecting the periodic profile of the reinforcement.

Among the methods for improving technological processes, the Value Engineering Analysis (VEA) is the most effective. This article presents the main results of an VEA analysis of the concrete works process. The purpose of the study is to conduct a morphological, structural, and functional analysis of the process, evaluate costs, and identify areas for improvement. At the first stage, a morphological classification of rein-forced concrete technology was created, covering various options for the technology. A preliminary analysis of existing technologies has been conducted. Based on the VEA of traditional technology, the functions, ranks, disadvantages, and priorities of operations have been identified.
It has been shown that by identifying the cause-and-effect relationships between the shortcomings of existing technology, key problems can be identified and priorities for improving operations can be clarified. A comparative analysis of various technologies for sliding and non-removable forms, shotcrete, 3D printing, and the method of low-lying concrete is conducted.