International Science and Technology Journal

This study investigates the impact of water-cooling versus conventional air-cooling on the compressive strength of concrete after exposure to high temperatures (800C0) for 15 minutes in an electric furnace at the Libyan Iron and Steel Company. The concrete mixtures utilized fine aggregates sourced from sand quarries in the Aburoya area of Misurata City and coarse aggregates from a quarry near Bani Walid City. A total of 27 samples were prepared and subjected to a 28-day moisture treatment. The samples were categorized into three groups based on their target compressive strengths: C25, C30, and C35, with nine samples in each group. For each group, six samples were exposed to high temperatures; three were then cooled immediately with water, while the remaining three were allowed to cool gradually at room temperature. An additional three samples were maintained as reference specimens that did not undergo high-temperature exposure. Upon testing, the results indicated that the samples cooled by water exhibited lower compressive strength compared to those that were gradually cooled at room temperature. Additionally, the reference samples demonstrated the highest compressive strength. Notably, the findings revealed an inverse relationship between the cooling method and concrete strength, with higher compressive strengths corresponding to decreased overall strength due to the cooling methods applied.............. Keywords:.......... High temperatures, Water cooling, Conventional air-cooling, Compressive strength, Reference samples.