Properties of Roller Compacted Concretes with Fly Ash


Abstract: In this study, brief information on zero slump concrete, which is not in common use in Turkey, is given. Zero slump concrete, also known as roller compacted concrete (RCC), is produced at a very low water-binder ratio. The vibrating slump method for determining the water-binder ratio of RCC is discussed. A laboratory investigation is carried out to assess the properties of RCC, which is a cost-effective and an attractive material for pavements. The strength characteristics of the concrete studied are presented. In the investigation, two fly ashes are employed to provide savings on cement. The influences of loss on ignition and the replacement ratio of fly ash as well as curing condition on the properties of RCC containing fly ash are assessed. The results show that a fly ash concrete having a similar strength value to that of conventional concrete can be produced at a 50% (by mass) replacement of cement by fly ash, provided that the fly ash used complies with the relevant standards. Fly ash concrete can also be produced with satisfactory strength development at a 70% replacement ratio (by mass). Loss in ignition content of fly ash was found to increase the mixing water, thus resulting in a reduction in strength development. The relation between the strength characteristics of RCC containing fly ash was found to be similar to that of conventional concrete. Considering strength and other properties, it was concluded that the concrete studied can be used for road paving material.

Keywords: Fly ash, RCC, Strength, Loss on ignition, Vibrating slump Test

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