Strength and Crack Resi Stance of Reinforced Concrete Beam Structures Under the Action of Low-Cycle Loads of Constant Sign and Cyclic Alternating Loadings of High Levels

Abstract

To investigate and to analyze the behavior of the areas near supports of reinforced concrete beam elements under the action of low-cycle loads of constant sign and repeated alternating loadings taking into account the influence of constructive factors and factors of external action for the future using of obtained results for improvement of calculated engineering technique. Methodology. Three series of experiments were performed to research this problem. Test specimens are reinforced concrete beams of rectangular cross section with sizes 200100 mm,

Influence of Intermittent Cyclic Loading on Reinforced Concrete Resistance Model

“…The presented theoretical data were compared to experimental data obtained by previous studies [10,11]. The character of deformation, cracking, and destruction of specimens, completely confirmed the considered physical models and the possibility of using the proposed calculation apparatus.…”

“…With consideration to the relevance of the chosen research topic and the need to update the research data within the framework of these studies, many scientists have focused on this issue. Reports of experiments found by literature review [2][3][4][5][6][7][8][9][10][11][12] indicate that repeated cyclic loading has a unique effect on the operating character of reinforced concrete structures. When exposed to the mentioned type of loading deflection valuesand the width of opening the normal and inclined cracks of elements increases, on average, by 15…20%, deformation values of the reinforcement and concrete also increases by 10…15%, and the bearing capacity of reinforced concrete structures decreases by approximately 20%.…”

“…Mirsayapov [2] and various researchers [10,11] have shown that with c0 / h0 > 2, the exhausting destruction of areas near the supports of bending elements occurs by forming a critical inclined crack, whose position is associated not only with the points of application of the external force and support reaction, but also with the internal force factors arising in the area between the support of an element and the location of concentrated force action (in moments and with transverse forces). If 1,2 <c0 / h0 ≤2, the nature of the formation and the development of cracks, as well as the exhausting destruction in this area during the specified loading, has an impact on the internal force factors and the local stress concentration in the relevant areas near the points of concentrated external forces.…”