THE METHOD OF RELIABILITY EVALUATION OF REINFORCED CONCRETE BEAMS, STRENGTHENED BY REINFORCED CONCRETE JACKET

Abstract

The technical literature (scientific articles, normative documents, manuals and recommendations) on the topic of theoretical research is analyzed and, on the basis of this analysis, the problems, which are not sufficiently studied as of today, are highlighted.

On the basis of the calculeted model of normal cross section according to engineering methodology, adaptation of the existing methodology of reliability design and also using the fundamental thesis of probability theory, including the recommendations of its use for building constructions, the principal methodology of reliability evaluation (for determining the quantitative indices of reliability) of rectangular reinforced concrete (RC) beams, strengthened by RC jacket under loading, which simulating the real conditions of reconstruction, is developed.

According to the developed method, the number of controlled stochastic parameters of reserve of load capacity of RC beams after strengthening, is proposed. Among them are the following: compressive strength of concrete of existing beam and strengthening jacket, tensile strength and compressive strength of reinforcing bars (variability of strength parameters); dimensions of main and additional cross section (variability of geometric parameters). Additionally, the number of controlled stochastic parameters of acting loading level of RC beam at the moment of strengthening, is also proposed (variability of the coefficients of use of cross sections of reinforcing bars and concrete of strengthening jacket).