Performance of Segmental Post-Τensioned Concrete Beams Exposed to High Fire Temperature

H. M. Hekmet, A. F. Izzet

Abstract


The present study illustrates observations, record accurate description and discussion about the behavior of twelve tested, simply supported, precast, prestressed, segmental, concrete beams with different segment numbers exposed to high fire temperatures of 300°C, 500°C, and 700°C. The test program included thermal tests by using a furnace manufactured for this purpose to expose to high burning temperature (fire flame) nine beams which were loaded with sustaining dead load throughout the burning process. The beams were divided into three groups depending on the precast segments number. All had an identical total length of 3150mm but each had different segment number (9, 7, and 5 segments), in other words, different segment lengths. To simulate genuine fire disasters, the nine beams were exposed to high-temperature flames for one hour along with the control specimens. The selected temperatures were 300°C (572°F), 500°C (932°F), and 700°C (1292°F) as recommended by the standard fire curve (ASTM–E119). The specimens were cooled gradually at ambient laboratory conditions. The performance of the prestressed segmental concrete beams through the burning process was described with regard to the beams camber, spalling, and occurred deterioration.


Keywords


burning temperature, fire flame; gradual cooling; segmental beam

Full Text:

PDF

References


M. Al-Gorafi, A. Ali, I. Othman, M. Jaafar, M. Anwar, “Externally Prestressed Monolithic and Segmental Concrete Beams under Torsion: a Comparative Finite Element Study”, IOP Conference Series: Materials Science and Engineering, Vol. 17, 2011

C. Sivaleepunth, J. Niwa, D. Nguyen, T. Hasegawa, Y. Hamada, “Shear Carrying Capacity of Segmental Prestressed Concrete Beams”, Doboku Gakkai Ronbunshuu E, Vol. 65, No. 1, pp. 63-75, 2009

D. Nguyen, K. Watanabe, J. Niwa, T. Hasegawa, “Modified Model for Shear Carrying Capacity of Segmental Concrete Beams with External Tendons”, Doboku Gakkai Ronbunshuu E, Vol. 66, No. 1, pp. 53-67, 2010

M. Algorafi, A. Ali, I. Othman, M. Jaafar, M. Anwar, “Experimental study of externally prestressed segmental beam under torsion”, Engineering Structures, Vol. 32, No. 11, pp. 3528-3538, 2010

Y. Chan, X. Luo, W. Sun, “Compressive strength and pore structure of high-performance concrete after exposure to high temperature up to 800°C”, Cement and Concrete Research, Vol. 30, No. 2, pp. 247-251, 2000

C. Poon, S. Azhar, M. Anson, Y. Wong, “Comparison of the strength and durability performance of normal- and high-strength pozzolanic concretes at elevated temperatures”, Cement and Concrete Research, Vol. 31, No. 9, pp. 1291-1300, 2001

B. Georgali, P. Tsakiridis, “Microstructure of fire-damaged concrete. A case study”, Cement and Concrete Composites, Vol. 27, No. 2, pp. 255-259, 2005

F. Aslani, “Prestressed concrete thermal behaviour”, Magazine of Concrete Research, Vol. 65, No. 3, pp. 158–171, 2013

L. Zhang, Y. Wei, F. Au, “Mechanical Properties of Prestressing Steel at Elevated Temperature and After Cooling”, Australasian Conference on the Mechanics of Structures and Materials, Southern Cross University, Australia, December 9-12, 2014

I. Fletcher, S. Welch, J. Torero, R. Carvel, A. Usmani, “Behaviour of concrete structures in fire”, Thermal Science, Vol. 11, No. 2, pp. 37-52, 2007

M. Abramowicz, R. Kowalski, “Residual Mechanical Material Properties for the Reassessment of Reinforced Concrete Structures After Fire”, 9th International Conference on Modern Building Materials, Structures and Techniques, Vilnius, Lithuania, May 16-18, 2007

J. Outinen, P. Makelainen, “Mechanical properties of structural steel at elevated temperatures and after cooling down”, Fire and Materials, Vol. 28, No. 24, pp. 237-251, 2004

W. Dias, “Some properties of hardened cement paste and reinforcing bars upon cooling from elevated temperatures”, Fire and Materials, Vol. 16, No. 1, pp. 29-35, 1992

K. Umran, Fire Flame Exposure Effect on Some Mechanical Properties of Concrete, MSc Thesis, Babylon University, 2002

M. Kadhum, “Effect of Burning by Fire Flame on the Behavior of Reinforced Concrete Beam Models”, Journal of Babylon University, Vol. 21, No. 5, 2011

J. J. Myers, W. L. Bailey, “Seven-Wire Low Relaxation Prestressing Tendon Subjected to Extreme Temperature: Residual Properties”, International Journal of Engineering Research and Science & Technology, Vol. 4, No. 3, pp. 223-239, 2015

R. Jansson, “Fire spalling of concrete – A historical overview”, MATEC Web of Conferences, Vol. 6, Article ID: 01001, 2013




eISSN: 1792-8036     pISSN: 2241-4487