| Title |
An Experimental Study on Spalling Causes of High Strength Concrete |
| Authors |
Lee Jae-Sung ; Chung Kyung-Soo |
| Keywords |
Fire ; High Strength Concrete ; Spalling ; Vapor Pressure ; Thermal Stress |
| Abstract |
High strength concrete (HSC) experiences frequently spalling under high temperatures with the fast heating rate such as a fire. The spalling causes the severe reduction of the cross sectional area with the exposure of the reinforcing steel, which originates a fatal problem in the structural safety. Two fundamental mechanisms on the explosive spalling are the vapor pressure build-up mechanism and the thermal stress mechanism. The vapor pressure build-up mechanism occurs due to an increase of the vapor pressure within the concrete while the thermal stress mechanism occurs due to a steep of the thermal gradient within the concrete. Various studies have been performed on the spalling of high strength concrete (HSC). In many test programs for high strength concrete (HSC), the specimens experienced explosive spalling, but not all, during the fire test. There were no clear answers for why spalling did not occur in all high strength concrete (HSC) specimens. The better understanding on the spalling is essential to provide the fundamental clues of spalling protections. The purpose of this study is to examine the main factor on the spalling with high strength concrete (HSC) specimens. In this study, the test results show that the spalling is only possible under the combination of the vapor pressure build-up mechanism and the thermal stress mechanism. |