Investigation of Fire Damaged Reinforced Concrete Walls with Axial Force

Reinforced concrete (RC) shear wall system of residential buildings is popular in South Korea. RC walls are subjected to axial forces in common and the effect of axial forces on the strength loss of the fire damaged walls has not been investigated. This paper aims at investigating temperature distribution on fire damaged concrete walls having different axial loads. In the experiments, a variable of specimens is axial force ratio. RC walls are fabricated with 150mm of wall thicknesses, 750mm of lengths and 1,300mm of heights having concrete strength of 24MPa. After curing, specimens are heated on one surface with ISO-834 standard time-temperature curve for 2 hours and temperature distributions during the test are measured using thermocouples inside the walls. The experimental results show that the temperature of the RC walls exposed to fire increases as axial force ratio increases. To verify the experiments, finite element (FE) models are generated for coupled temperature-structure analyses. The analytical results of thermal behaviors are in good agreement with the experimental results. The predicted displacement of the walls decreases when the axial force increases. 





References:
[1] S. J. Lee, “A Study on Structural Behaviors of Fire-Damaged Reinforced Concrete Beams with Normal Strength Concrete,” M.S. thesis, Ewha womans university, Seoul, 2003.
[2] E. G. Choi, Y. S. Shin and H. S. Kim, “Structural damage evaluation of reinforced concrete beams exposed to high temperatures,” Fire Protection Engineering, 0(00) pp 1–17, April. 2013
[3] E. G. Choi and Y. S. Shin, “The structural behavior and simplified thermal analysis of normal-strength and high-strength concrete beams under fire,” Engineering Structures, vol. 33, Issue 4, pp 1123-1132, April. 2011
[4] J. Y. Kang, H. S. Kim and Y. S. Shin, “Analytical studies on temperature distributions of one side heated load bearing RC walls,” in proceeding of International Conference of Asian Concrete Federation, Seoul, Korea, September. 2014
[5] Crozier, Damian A. and Sanjayan, Jay G., “Tests of Load-Bearing Slender Reinforced Concrete Walls in Fire,” American Concrete Institute Structural Journal, vol. 97 No. 2, pp.243-251, 2000
[6] T. Ngo, S. Fragomeni, P. Mendis and B. Ta, “Testing of Normal- and High-Strength Concrete Walls Subjected to Both Standard and Hydrocarbon Fires,” American Concrete Institute Structural Journal, vol. 110 No. 3, pp.503-510, 2013
[7] KS F 2257-1, Methods of fire resistance test for elements of building construction-general requirements, Korean Agency for Technology and Standards, 2014
[8] KS F 2257-4, Methods fire resistance test for elements of building construction ― specific requirements for loadbearing vertical separating elements, Korean Agency for Technology and Standards, 2015
[9] KS F 2403, Standard test method for making and curing concrete specimens, Korean Agency for Technology and Standards, 2014
[10] N. W. Kim, I. N. Park, S. K. Lee, Y. J. Lee, D. G. Jung and S. H. Lee, "Reinforced Concrete Structure by Ultimate Strength Design," Kimoondang, pp 251-252, 2004