International Science and Technology Journal

Noticeable that the concrete mixture industry is in constant development in conducting some research and studies to improve alternatives and additions that lead to the produces of high quality and strength of concrete. As well as building construction processes keep up with the development, that in the development of construction depinded on the development of the materials what is into, especially concrete is one of the most important materials for building and construction. As know to engineers and researchers that regular concrete consisting of natural aggregates is relatively heavy in the design of concrete structures, especially High Rise Building structures, which leads to an increase in weight and subsequently an expensive design for the structure of the concrete building and foundations. However that, the process of manufacturing natural aggregates leads to air pollution, thus that the idea of studying alternatives to aggregates to fulfill the purpose of reducing the weight of concrete as well as preserving the environment from the remnants of the manufacture of natural aggregates and that reasons the study. In this study used of fly ash FLY ASH and studied some of properties and effects on the properties of concrete in wherever of strength, durability and workability. During this studying of the fly ash characteristics for the formation of lightweight aggregates, advantages is that it gives good workability has been resulting, better than that the case of using natural aggregates, wherever facilitates the process of mixing, transporting and placing concrete. observed that it had a lower compressive strength than in the case of using natural aggregates thus that possible to improve the strength significantly by reducing the of water / cement ratio. as some studies showed that the ratio of water / binder has a important effect on water permeability and absorption, the properties of concrete thus of durability and strength had been develpment by control in this ratio. Key words: light Weight, Normal Weight, Concrete, Fly Ash