الفهرس | Only 14 pages are availabe for public view |
Abstract Self-Compacting Concrete (SCC) is a new category of High Performance Concrete with high workability and flowability but without segregation. This concrete has the advantages of being cast easily under its own weight without the need of any external compacting energy. In addition, SCC is made of same ingredients of Normal Concrete (NC) in addition to extra fine material and special type of super-plasticizer. The current research studied the properties of SCC containing different powders types (fly ash, silica fume and metakaoline) and different aggregate types (gravel, basalt and dolomite) compared with that of SCC without any powders. The research program consists of 48 concrete mixes and divided into 6 groups. All mixes were designed to have a constant water/powder ratio of 0.45 and a constant content of super-plasticizer (sikavisco-crete 5920) of 1.5% by weight of powder, a trial mixes were done to obtain the previous ratios to ensure the self- compactability conditions. And all mixes were made from locally available material. Fresh properties of SCC were tested and the results indicated that all mixes satisfied the EFNARC limitations for slump flow time (Tso), slump flow diameter (D), the L-box height ratio (H2/Hj), and V -Funnel flow time. Also the hardened properties of SCC were tested and the results indicated that, mixes containing dolomite as a coarse aggregate gave the highest values for both compressive and tensile strength on the other hand, mixes containing gravel as a coarse aggregate gave the lowest values. Also, the results indicated that incorporating FA decrease the compressive strength at 3 days and show an increase at 28 days , while SF increase the compressive strength at 3 and 28 days and MK show an increase at early ages and a slight changes at 28 days. And the incorporation of theses powders has a little effect on tensile strength. II ABSTRACT Self-Compacting Concrete (SCC) is a new category of High Performance Concrete with high workability and flowability but without segregation. This concrete has the advantages of being cast easily under its own weight without the need of any external compacting energy. In addition, SCC is made of same ingredients of Normal Concrete (NC) in addition to extra fine material and special type of super-plasticizer. The current research studied the properties of SCC containing different powders types (fly ash, silica fume and metakaoline) and different aggregate types (gravel, basalt and dolomite) compared with that of SCC without any powders. The research program consists of 48 concrete mixes and divided into 6 groups. All mixes were designed to have a constant water/powder ratio of 0.45 and a constant content of super-plasticizer (sikavisco-crete 5920) of 1.5% by weight of powder, a trial mixes were done to obtain the previous ratios to ensure the self- compactability conditions. And all mixes were made from locally available material. Fresh properties of SCC were tested and the results indicated that all mixes satisfied the EFNARC limitations for slump flow time (Tso), slump flow diameter CD), the L-box height ratio (H2/H,), and V -Funnel flow time. Also the hardened properties of SCC were tested and the results indicated that, mixes containing dolomite as a coarse aggregate gave the highest values for both compressive and tensile strength on the other hand, mixes containing gravel as a coarse aggregate gave the lowest values. Also, the results indicated that incorporating FA decrease the compressive strength at 3 days and show an increase at 28 days , while SF increase the compressive strength at 3 and 28 days and MK show an increase at early ages and a slight changes at 28 days. And the incorporation of theses powders has a little effect on tensile strength. |