Author(s): Thananun Phuwadolpaisarn | Sayan Sirimontree | Boonsap Witchayangkoon
Journal: International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies
ISSN 2228-9860
Volume: 4;
Issue: 4;
Start page: 241;
Date: 2013;
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Keywords: Flexural rigidity Post-Tension | Strengthening | Repair Prestress | Structural rigidity | Beam girder | Full scale test.
ABSTRACT
Prestressed concrete beams can be damaged by overloading beyond cracking stage leading to the reduction of flexural rigidity and excessive deflection. The progressive of damage, crack and permanent deflection can be occurred at the high level of load after cracking. Structural performance of damaged girder can be recovered and improved by external post tension. The level of external prestressing force required in strengthening depends directly on the level of damage due to overloading. This research studied the effect of levels of damage on flexural rigidity, crack and deflection of the test girder. Three levels of damage can be expressed in terms of 0.65, 0.75 and 0.85 times the predicted ultimate load of the test beam. Three levels of external prestressing forces (2, 2.5 and 3 times of the internal prestressing force applied in undamaged reference beam) are applied in strengthening at each level of damage. The results show that reduced flexural rigidity, increased permanent deformation and crack width due to overloading can be recovered by external post tension. Strengthening by means of external post tension can be effectively applied to the damaged beam at the level of damage not more than 0.65 times of predicted ultimate load.
Journal: International Transaction Journal of Engineering, Management, & Applied Sciences & Technologies
ISSN 2228-9860
Volume: 4;
Issue: 4;
Start page: 241;
Date: 2013;
VIEW PDF
DOWNLOAD PDF Original pageKeywords: Flexural rigidity Post-Tension | Strengthening | Repair Prestress | Structural rigidity | Beam girder | Full scale test.
ABSTRACT
Prestressed concrete beams can be damaged by overloading beyond cracking stage leading to the reduction of flexural rigidity and excessive deflection. The progressive of damage, crack and permanent deflection can be occurred at the high level of load after cracking. Structural performance of damaged girder can be recovered and improved by external post tension. The level of external prestressing force required in strengthening depends directly on the level of damage due to overloading. This research studied the effect of levels of damage on flexural rigidity, crack and deflection of the test girder. Three levels of damage can be expressed in terms of 0.65, 0.75 and 0.85 times the predicted ultimate load of the test beam. Three levels of external prestressing forces (2, 2.5 and 3 times of the internal prestressing force applied in undamaged reference beam) are applied in strengthening at each level of damage. The results show that reduced flexural rigidity, increased permanent deformation and crack width due to overloading can be recovered by external post tension. Strengthening by means of external post tension can be effectively applied to the damaged beam at the level of damage not more than 0.65 times of predicted ultimate load.
