Prediction of the Remaining Service Life of Reinforced Concrete Structures

The main indicators of durability, which characterize the time of operation of the structure before the onset of an emergency condition, are the total service life and the remaining service life, the determination of which allows a more reasonable approach to the issue of planning current or major repairs in the building. The most common engineering techniques that allow predicting the remaining service life for reinforced concrete structures are considered: according to standard terms and analogous objects, according to external signs, based on changes in reserve coefficients and strength criteria. Their modifications are given for a number of techniques. Based on the results of the analysis of the methods, their main advantages and disadvantages were established. As a proposal to improve the existing approaches, a methodology is proposed in which the interval between visual examinations is taken for the remaining period of operation

Improving the Regulatory Framework for the Standardization of Precast Concrete Structures

The article considers the structure of regulatory documents for precast reinforced concrete structures. The directions of development of the regulatory framework by updating and developing standards (GOST and GOST R) for certain types of precast reinforced concrete structures are given. It is noted that the purpose of the development and updating of standards is to establish current technical requirements for precast reinforced concrete structures, due to changes in the regulatory framework for the design of reinforced concrete structures, in particular in SP 63.13330.2018 "SNiP 52-01-2003 Concrete and reinforced concrete structures. The main provisions", and the improvement of technological requirements. In recent years, JSC "Tsniipromzdaniy" has developed and updated more than 20 standards (GOST and GOST R) only by the Department of Structural Systems No. 1, in which a number of new provisions have been adjusted and developed based on the analysis of domestic and foreign regulatory framework, modern manufacturing and installation technologies. It is advisable to develop standards for individual structures taking into account the requirements given in the fundamental GOST 13015-2012 "Concrete and reinforced concrete products for construction. General technical requirements. Rules of acceptance, marking, transportation and storage". The structure of the standard standard for precast reinforced concrete structures is considered

Development of a Stress Sensor for Solids

The paper presents the results of experimental design of a cortex of the embedded stress sensor, which allows to determine stresses in the cross-section of large-scale laboratory monolithic structures made on the basis of mineral and polymer binders (concrete, gypsum, etc.). The objectives of the design were to develop a constructive solution of the stress sensor housing based on strain gauges, which has small dimensions, low manufacturing cost, as well as high resolution and stability of readings over the entire sensitivity area (stress up to 400 kgf/cm2).The stress sensor allows to determine the stress in laboratory structures with high accuracy, without significantly affecting the stress-strain state of the section at different stages of operation of the structural element