Evaluation of dry mortar ratio as mix design parameter for steel fibre reinforced self compacting co 2017-09-18

dry mortar

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  1. Alex
    Steel fibre reinforced concrete has been successfully used in several types of construction due to the fact that steel fibres adding improves the durability and mechanical properties of hardened concrete, namely the flexural strength, toughness, impact strength, resistance to fatigue, vulnerability to cracking and spalling [1]. However, it is also known that the addition of steel fibres reduces the workability of normal fresh concrete.

    The applicability of steel fibres in self-compacting concrete (SCC) has been investigated and has proven to be feasible [2–5]. The inclusion of fibres into the SCC mix design was studied under different concepts. Some examples can be mentioned: the concept of perturbation volume on the compressible packing model due to the fibres addition [6]; the concept of equivalent specific surface diameter applied to the fibres and used to optimize the solid skeleton [2] and the concept of maximum fibre factor that is related to risk of fiber reinforced concrete blocking through an equivalent bar spacing [7].

    Other studies concerning the steel fibre reinforced self compacting concrete (SFRSCC) behaviour attested that the self compactability is remarkably sensitive to the fibre type and fibre contents [8]. In turn, the fibre content and fibre type are mainly defined by the high flowability and segregation resistance of fresh mixtures [9]. The improvement of SCC workability is possible by the use of supplementary cementitious or inert materials, such as fly ash, which can increase the viscosity and reduce the cost of SCC [10]. The type and content of fibres are identified by the product of fibres volume
    (Vf) and fibre aspect ratio (L/D), so called fibre factor (Vf L/D). Higher the fibre factor, harder it will be to attain self-compactable characteristics. Thus, the fibre factor limit would be dependent on the composition and proportion of the SCC matrix.