Öngerilmeli Beton Elemanlarda Gerilme Analizi

Öz

Öngerilmeli beton elemanları yapım elemanı olarak yaygın bir şekilde kullanılmaktadır. Öngerilmeli beton elemanlarda üretim aşamasında oluşturulan etkili öngerilme seviyeleri elemanın bazı bölgelerinde yüksek seviyelere çıkabilmektedir. Bu durumun fotoelastik yöntemlerle modellenmesi diğer deneysel metodlarla elde edilmesi mümkün olmayan gerilme analizlerine imkan vermektedir. Bu çalışmada öngerilmeli betonun fotoelastik yöntemlerle gerilme analizi yapılmış olup elemanın bazı bölgelerinde üretimden kaynaklanan yüksek öngerilme seviyelerinin malzemenin dayanımını aşabildiği anlaşılmaktadır. Güvenli tasarım sınırlarında üretilmesi gereken öngerilmeli beton elemanların bahsedilen bölgelerde önlemler alınması gerektiği çalışma sonucu anlaşılmaktadır.

Anahtar Kelimeler

• Öngerilmeli beton, fotoelastisite, termoelastisite

-

Öz

In practice, pre-tensioned concrete members are widely being used as structural elements. Effective pre-stresses in particular regions of pre-tensioned concrete members can have high values in production process. Modeling pre-tensioned concrete members with using photoelastic methods may lead to detailed stress analysis which is not likely possible in most of the other experimental techniques. This study deals with stress analysis of prestressed pre-tensioned concrete members with photoelastic modeling. It is seen that in some regions of the pre-tensioned concrete members, designed pre-stresses may have higher values than the nominal strength of the material. It is also infered that, in order to sustain safety design margins sufficient precautions must be taken into account for the considered regions

Anahtar Kelimeler

• Prestressed concrete, photoelasticity, thermoelasticity

Kaynakça

1. - Freyssinet, E (1954) The birth of prestressing (Translated by Harris AJ). Prestressed concrete, Auckland
2. - Base, GD (1957) Some tests on the effect of time on transmission length in pre-tensioned concrete. Mag Concrete Res 9(26):73-82
3. - Arthur, PD, Ganguli, S (1965) Tests on end-zone stresses in pre-tensioned concrete I beams. Mag Concrete Res 17(51):85-96
4. - Martí-Vargas, JR, García-Taengua, E, Caro, LA, Serna P (2014) Measuring specific parameters in pretensioned concrete members using a single testing technique. Measurement 49:421-432
5. - Christodoulides, SP (1955) A two-dimensional investigation of the end anchorages of post–tensioned concrete beams. Struct Eng pp 120-133
6. - Rasheeduzzafar, Allison, IM, Al-Saadoun SS (1984) A photoelastic investigation of anchorage bearing stresses. Mag Concrete Res 36(127):81-91
7. - Linger DA and Bhonsle SR (1963) An investigation of transfer length in pretensioned concrete using phoelasticity. PCI Journal, August 1963 pp. 13-30
8. - Boley, BA, Weiner, JH (1960) Theory of thermal stresses. Wiley, New York

9. - Muskhelishvili, NI (1963) Some basic problems of the mathematical theory of elasticity, P. Noordhoff Ltd., Groningen
10. - Donmez A, Ataoglu S, Aldemir U, Artan R, Abdulaliyev Z, Residual Stresses in the Prestressed Concrete Elements, 11th International Congress on Advances in Civil Engineering, ACE2014, Istanbul, 2014
11. - Abdulaliyev Z, Bakioglu M, Ataoglu S, Kurtkaya Z, Gulluoglu AN, Thermal Stress Concentration in Plates from Different Materials, Journal of Aircraft, 49 (3), 941-946, 2012 DOI: 10.2514/1.C031661
12. - Frocht, MM (1947) Photoelasticity. Wiley, New York
13. - Goodier, JN (1957) Thermal stress and deformation. J Appl Mech-T ASME, 24(3) 467-474
14. - Timoshenko, SP., Goodier, JN (1970) Theory of elasticity, McGraw-Hill, Singapore
15. - Papkovich, PF (1939) Elasticity theory, Oborongiz, Leningrad-Moscow
16. - Horvay, G. 1954. Thermal stresses in rectangular strips. Proc. II. National Cong. of
17. Appl. Mech., ASME, New York, N.Y.