SCC mixes with limestone and chalk powder - The Indian experience

摘要

The use of limestone powder and chalk powder as fillers in self-compacting concrete (SCC) was investigated. Flow and strength characteristics of the concrete mixes prepared using these materials were studied. With minor adjustments in the superplasticiser dosage, it was possible to develop concrete mixes with suitable self-compactability by using limestone powder. The morphology of the powders had a significant influence on flow behaviour and the best deformability was obtained in the SCC mixes containing the fine limestone powder whereas the coarser chalk powder gave poor performance. Besides particle size, the shape of the powder particles also had a significant influence on deformability. The deformability of the SCC mix with the coarser but spherically shaped fly ash particles was comparable to that of the SCC mixes with the much finer but irregularly shaped limestone particles. The slump flow retentivity of the SCC mixes with the Glenium 51 superplasticiser was checked over two hours after casting and was found to be satisfactory except in the mixes with the coarser chalk powder. However, the plastic viscosity of the mixes with higher powder addition levels was found to increase rapidly with time. The compressive strength of the SCC mixes containing the fine limestone powder was significantly greater than that of the control SCC mix with the same powder content.