All precast concrete producers can now use a group of materials called fly ash to improve the quality and durability of their products. Fly ash improves concrete’s workability, cohesiveness, finish, ultimate strength and durability as well as solves many problems experienced with concrete today and all for less cost. Fly ash, however, must be used with care. Without adequate knowledge of its use and taking proper precautions, problems can result in mixing, setting time, strength development and durability. The fly ash mix content with different percentage will be used in this study. Therefore, in order to study the strength and durability of each types of fly ash when partially mix with concrete, the bricks will be exposed to different atmo...