CALCULATION OF PRE-STRESSING LOAD MOMENT OF A HIGH-PERFORMANCE REINFORCED CONCRETE ELEMENT BASED ON A NONLINEAR DEFORMATION MODEL

The article is a part of the development of the method for reinforced concrete structural analysis based on a nonlinear deformation model, in particular, for analysis of high-performance pre-stressed concrete elements. The possibility to apply a nonlinear deformation model to select parameters of reinforced concrete pre-stress elements was analyzed, and relevant calculations were performed. Three-line diagrams of В60 concrete deformation, built according to the recommendations and assumptions of SP 63.13330.2012 were used. Two types of the cross-section of a reinforced concrete element were studied: with symmetrical and nonsymmetrical reinforcement. For each cross-section type calculations for three phases were carried out: an elastic strain phase, a plastic strain evolvement phase, and a plastic strain phase. At each phase, reinforced concrete element stress and strain behavior was analyzed. Calculations were limited by the condition of lack of cracks in the reinforced element caused by the pre-stressing load. Based on these data obtained as the calculation results for a non-linear deformation model, calculation of pre-stressing load was carried out in compliance with requirements and recommendations of SP 63.13330.2012 and SNiP 2.03.01-84*. Comparing the data obtained according to different methods, significant divergence in values of pre-stressing load was found out (30,3% - 42,6%) The divergence in values compared with the values calculated according to recommendations in SP 63.13330.2012 is constant at all phases of reinforced element behavior , and divergence in values obtained as per SNiP 2.03.01-84* slowly decreases with the increase of pre-stressing loads and inelastic deformation in the tensile zone of concrete.

нелинейная деформационная модель бетона, предварительное напряжение, диаграмма деформирования бетона, напряженно - деформированное состояние, усилие предваритель-ного обжатия, nonlinear concrete deformation model, pre-stressing, concrete deformation diagram, stress-strain behavior, pre-stressing load

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