Paper Title
Investigating the Effect of Different Forms of Gravel as an Aggregate on Compressive Strength of Concrete

Abstract
Concrete has high importance as building materials in the modern especially with different material reinforced to become an armed material. It consists of raw materials, cement, sand with the addition of types of gravel, and water which are available and easy to work. A good mix was prepared to achieve the best concrete properties as they gradually harden with time. In this project concrete was used different size(coarse – 3/4 inch, fine – 1/2 inch and crushed), and different forms (rounded, longitudinal and irregular) of gravel and study their effect on the compressive strength. Almost aggregate accupate 60-70% of concrete volume, that affect the physical and mechanical characteristic of concrete to a great extent . The samples were prepared for each size and shape of the gravel, after the process finishing, kept the samples in the maturation basin for a period of (7,14, 28) days. Then the compression test was carried out. The difference in size and shape of the aggregates has been shown to have some influence on the strength of concrete. It was found that the samples of the different sizes were resistance to compression higher than the compression of the samples with different shapes. The gain of using both crushed and irregular gravel is about 30-36% depending on grained size and shape with different curing time. Key words - Portland cement, gravel, compressive strength