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Evaluation of concrete linear creep in determination of stress state and steel prestress losses in concrete members/Betono tiesinio valkšnumo įvertinimas, nustatant gelžbetoninių elementų įtempimų būvį ir armatūros išankstinio įtempimo nuostolius
Determination of stress-strain state imposed by concrete linear creep and specification of steel prestress losses in linear prestressed concrete member is discussed in this article. Particularities of regulations of the Code acting in Lithuania [1] and of Eurocode [2] are analysed and a modified method for calculation of steel prestress losses due to concrete linear creep in prestressed concrete linear members suitable for assessment of Code regulations is presented. Also, the method is used for analysis of results of long-term tests of reinforced concrete members.In Lithuania, a code based on investigations of prestressed concrete members is used for calculation of steel prestress losses due to concrete creep. Therefore calculation of losses is associated with stress-strain state of the member in timet in empirical way only and time dependent stress-strain state is adjusted by additional coefficients to take into consideration concrete creep. Analogous calculations of steel prestress losses by Eurocode are presented in a more general form and are based on creep theory. It is clear that in the first [1] and the second [2] cases the same change in stress-state is evaluated by different parameters. Therefore it is important to create a general method based on concrete creep characteristics.General case of eccentrically reinforced prestressed concrete linear member under the action of prestressing forces changing with time in relation to prestress losses due to concrete creep is analysed (Fig 1).Stress-strain time dependent state of such member with the changing concrete stress σb(t) and σ′b(t) is determined using well-known equations of equilibrium (1–4) and integral differential equations (7–8) for evaluation of concrete creep deformations [4–8]. These equations are solved by numerical method (9–10) dividing time period considered in intervals. In reference [9] a more particular solution method evaluating variation of interval magnitude in relation to accuracy of solution is presented.In such a way it is possible ...
Evaluation of concrete linear creep in determination of stress state and steel prestress losses in concrete members/Betono tiesinio valkšnumo įvertinimas, nustatant gelžbetoninių elementų įtempimų būvį ir armatūros išankstinio įtempimo nuostolius
Determination of stress-strain state imposed by concrete linear creep and specification of steel prestress losses in linear prestressed concrete member is discussed in this article. Particularities of regulations of the Code acting in Lithuania [1] and of Eurocode [2] are analysed and a modified method for calculation of steel prestress losses due to concrete linear creep in prestressed concrete linear members suitable for assessment of Code regulations is presented. Also, the method is used for analysis of results of long-term tests of reinforced concrete members.In Lithuania, a code based on investigations of prestressed concrete members is used for calculation of steel prestress losses due to concrete creep. Therefore calculation of losses is associated with stress-strain state of the member in timet in empirical way only and time dependent stress-strain state is adjusted by additional coefficients to take into consideration concrete creep. Analogous calculations of steel prestress losses by Eurocode are presented in a more general form and are based on creep theory. It is clear that in the first [1] and the second [2] cases the same change in stress-state is evaluated by different parameters. Therefore it is important to create a general method based on concrete creep characteristics.General case of eccentrically reinforced prestressed concrete linear member under the action of prestressing forces changing with time in relation to prestress losses due to concrete creep is analysed (Fig 1).Stress-strain time dependent state of such member with the changing concrete stress σb(t) and σ′b(t) is determined using well-known equations of equilibrium (1–4) and integral differential equations (7–8) for evaluation of concrete creep deformations [4–8]. These equations are solved by numerical method (9–10) dividing time period considered in intervals. In reference [9] a more particular solution method evaluating variation of interval magnitude in relation to accuracy of solution is presented.In such a way it is possible ...
Evaluation of concrete linear creep in determination of stress state and steel prestress losses in concrete members/Betono tiesinio valkšnumo įvertinimas, nustatant gelžbetoninių elementų įtempimų būvį ir armatūros išankstinio įtempimo nuostolius
Balevičius, Robertas (author) / Dulinskas, Eugedijus (author)
1999-12-31
doi:10.3846/13921525.1999.10531491
Journal of Civil Engineering and Management; Vol 5 No 6 (1999); 364-373 ; 1822-3605 ; 1392-3730
Article (Journal)
Electronic Resource
English
DDC:
690