الفهرس 
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Abstract
Introduction: Realizing higher strength concrete has been a target or a dream for researchers and engineers engaged in construction industry. In practice, the concrete with compressive strength higher than 50MPa at age of 28 days considered to be the high strength concrete . The SCC is defined as a concrete with high workability so that it can flow under its own weight without bleeding and segregation by reducing the water to powder ratio and adding super plasticizer (SP) and/or Viscosity modifying admixtures (VMA) .Andesite is the name used for a family of fine-grained, extrusive igneous rocks that are usually light to dark gray in color. However, ryolite is an extrusive igneous rock with a very high silica content. It is usually pink or gray in color.
-Research scope: Studying the effect of using a new type of coarse aggregate(Andesite and Ryolite)
on fresh and hardened concrete properties.
- Research objective: Producing a High strength Self compacting concrete (HSSCC) that consistently meets the requirements for workability and durability Utilizing a new type of aggregate (Andesite and Ryolite), Analysis the test results of concrete on its fresh statement. Studying the mechanical and chemical properties of concrete utilizing andesite and ryolite aggregate.
- Steps study: Tests were carried out on the material used in this study to determine the chemical and physical properties of these materials, the mixes were casted with different ratios of andesite and ryolite and compared the results of the fresh and hardened concrete tests with the gravel and dolomite mixes.
-Conclusions: Crushed stone and volcanic rocks (andesite and ryolite) needs more water than the gravel to achieve the fresh properties of SCC. Using the crushed stone (Dolomite) and the volcanic rocks (Andesite and Ryolite) as a coarse aggregate in HSSCC(cement content 500 kg/m3) may affect the compression strength positively. As the cement content increases(from 500 to 900 kg/m3) and the W/CM decreases (from 0.3 to 0.22), the properties of fresh SCC decreases.