Post-Fire Flexural Strength of The Fly Ash Concrete Beams and Rapid Cooling Down
Keywords:
Flexural strength performance, Flexural strength of the fly ash concrete, Post-Fire flexural strength of the fly ash concrete beamsAbstract
The purpose of this research is to test the post-fire flexural strength of the fly ash concrete beams and its rapid cooling down, as well as the effect of its exposure to heat. The test samples are three sets of 10×10×35 cm fly ash concrete beams which are 1) fly ash concrete beams, 2) fire-burnt of the fly ash concrete beams which cooled down rapidly (by soaking in the water), and 3) fire-burnt of the fly ash concrete beams which cooled down (in the air). For the experimental process, the fly ash concrete beams will be fire-burnt at the temperature of 400 degrees Celsius for 15, 30, and 45 minutes respectively. After that, the items will be brought to the standard flexural strength test of C78/C78M. The test results reveal that the flexural strength rate will decrease if the sample is being exposed to heat for a longer period of time, and the sample which is cooling down rapidly by soaking in the water will lose its flexural strength rate less than the sample which is left to be cooled down in the air. The reason was, leaving the items to cool down in the air, the item will have a rather high accumulated heat, resulting in a water evaporation in the fly ash concrete beams to occur continuously, leading to the subsiding of its flexural strength rate. The early age fly ash concrete is strength less valuable than concrete without fly ash, but at the long term it is strength higher than concrete without fly ash. However, if at high temperatures residual strength of due primarily to the reduced porosity.
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