الفهرس | Only 14 pages are availabe for public view |
Abstract Self-Compacting Concrete is an innovative concrete that does not require vibration for placing and compaction. It is able to flow under its own weight, completely filling formwork and achieving full compaction, even in the presence of congested reinforcement. One of the disadvantages of selfcompacting concrete is its cost, associated with the use of high volumes of Portland cement and use of chemical admixtures. One alternative to reduce the cost of self-compacting concrete is the use of mineral admixtures such as silica fume, fly ash and limestone powder as a cement replacement materials. When these mineral admixtures replace a part of the Portland cement, the cost of self- compacting concrete will be reduced especially if the mineral admixtures are waste or industrial by-product. This study presents the development of SCCs produced with binary, ternary and multi-systems of Portland cement, Fly Ash (FA), Silica Fume (SF) and limestone powder (LP) as a partial cement replacement material (CRMs) with different percentages and using local materials and investigate the fresh and hardened, fluid transport characteristics and microstructure of such concrete. Five series of concrete mixes containing binary, ternary and multi-system blends were designed and cast with a constant water/binder ratio of 0.35 and performance is measured and compared with control mix of Portland cement. Test results showed that SCC can be produced with binary, ternary and multisystems of Portland cement, Silica Fume (SF), Fly Ash (FA) and limestone iii powder (LP) as a partial cement replacement material (CRMs) with different percentages having satisfactory performance in the fresh state with compressive strength ranging from (37.5 – 90) Mpa at 90 days. The inclusion of (SF) and/or (FA) reduce the amount of superplasticizer necessary to achieve a given fluidity. But the inclusion of (LP) increase the amount of superplasticizer needed. However, the inclusion of (LP) in SCC mixes increases the segregation resistance. Keywords: |