INFLUENCE OF HIGH-STRENGTH REINFORCEMENT WITHOUT ADHESION TO CONCRETE ON STRENGTH OF CAST-IN-SITU BEAMLESS FLOORS

• Main Authors: Osipenko Yuri Grigoryevich, Kuznetcov Vitaliy Sergeevich, Shaposhnikova Yulia Alexandrovna
• Format: Article
• Language: English
• Published: Moscow State University of Civil Engineering (MGSU) 2017-08-01
• Series: Vestnik MGSU
• Subjects: strength; deflection; tensile reinforcement; monostrand; cast-in-situ beamless floors; rope; contour position of prestressed reinforcement; diagonal arrangement of prestressed reinforcement; guy rope
• Online Access: http://vestnikmgsu.ru/index.php/archive/article/download/3945

The influence and location of prestressed high-strength reinforcement without adhesion to concrete on the strength of a beamless floor panel is considered. The work is aimed at clarifying the methodology for calculating the strength of cast-in-situ beamless floor with mixed reinforcement, where reinforcement is used in a plastic shell of monostrend type without adhesion to concrete for the most complete use of the strength characteristics of the panel material. The aim of the study is to determine the level of influence and location of prestressed reinforcement without adhesion to concrete on the strength of a panel of cast-in-situ beamless floor, as well as comparison of the results obtained for the stresses of ropes in panels with contour and diagonal arrangement of prestressed reinforcement. The shape of the rope position is represented by a part of the parabola passing through the points of the rope support. On the support, the vertical and horizontal components of the reaction are determined by the longitudinal force in the rope and the exit angle of the guy rope. 9х9m cast-in-situ beamless floor panels in two variants were investigated: with diagonal and contour stressing steel. The values of increment in stresses in the ropes and the resulting values at various prestress and deflection levels, presented in the form of tables and graphs, have been calculated. According to the results of the study, the use of high-strength prestressed ropes without adhesion to concrete, as an additional working reinforcement, reduces deflections of the panels and lowers consumption of common reinforcement. The results indicate a relative decrease in efficiency of using rope strength along with an increase in the initial prestress level. From the point of ensuring load-bearing capacity, the contour positioning of ropes is preferable, due to more complete use of strength of high-tensile reinforcement. To meet the requirements of ultimate limit states, the establishment of the pre-stress level of ropes should be carried out taking into account probable achievement of the design stress in high-strength reinforcement .