Abstract:
In this study two concrete mixes were designed by using British standard method with different compressive strengths. The first mix design was created without additives with a compressive strength equal to 30 map. Equal to 40 maq. Then concrete cubes were casted and exposed to different temperature degrees. Moreover. These cubes have been tested by compressive machine and found that the loss in the compressive strength is increased by increasing temperature and time Also found that the losses in compressive strength is greater in concrete mixes with additives (super plasticizer). The remaining of compressive strength losses is increased above 50% in temperature degree of 300c. there fore. The study recommended that that the engineers must avoiding the use of chemical additives that help on ignition and design concrete mixtures with high compressive strength for production dense concrete to be used in structures for increasing spicily firing resistance.