PERUBAHAN PERILAKU MEKANIS BETON AKIBAT TEMPERATUR TINGGI

Fire resistance of concrete as building material is better than other material. It is caused by the thermal conductivity of concrete is low. However, concrete still has limitation. When the concrete is experienced to the height temperature for a long of time, it will be damage. The degree of damage is depended on various factor, such as the degree of temperature, duration of fired, or the concrete quality. This research is assumed to find out the change of concrete strength and modulus elasticity of the concrete after fired at various temperature and duration. Two different concrete strength, K225 and K350, are tested in this research. Both are fired at the temperature of 300°C, 600°C, and 900°C at the duration of 3 hours, 5 hours, and 7 hours. Result of this research indicated that the behaviour strength of concrete and modulus elasticity of concrete after fired is equal, that is decreasing. The degree of degradation is influenced by temperature achieved and duration.The higher the temperatur are the longer the duration, the rest of the strength tend to be smaller. For example, the fired at temperature 300°C during 3 hours, the rest of the srength concrete ± 71,8 %, and for duration 9 hours become ± 60,04%. The change of the strength of concrete and also modulus elasticity of concrete for different concrete quality are different although they are burned at the same temperature and duration. For example at temperature 600°C for 5 hours duration, strength of concrete K225 of the rest strength ± 36,40%, while K350 of the rest strength ± 24,46 %