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Specially processed steel cord (SC) macrofibres, each consisting of five twisted steel fibres, are used to improve the post-cracking behaviour of cementitious composites. The long steel cords have a large diameter, and are characterised by high tensile strength, frictional bond strength and flexural rigidity. In addition to these steel cord macrofibres, microfibres are used to enhance the snubbing strength and total tensile behaviour of the composite. The two specific hybrid fibre blends studied in the present paper are SC and polyethylene (PE), as well as SC and polyvinyl alcohol (PVA) fibres. The objectives of the current study are to explore the mechanisms by which fibres interact with the composite matrix, and to provide a rigorous characterisation of the performance achievable with hybrid-fibre-reinforced cementitious composites (HFRCCs). Cement-based composites containing large volume fractions (1·0∼2·3%) of various hybrid fibres were compared in terms of flow and fibre dispersion, as well as compressive, splitting tensile, flexural and uniaxial tensile properties. The workability of HFRCCs is governed by the high surface area of the microfibres. The results confirm that the flexural strength, tensile strength and ductility (pseudo-strain-hardening) of HFRCCs are tremendously improved in comparison with mortar or monofibre systems. Furthermore, there is a synergy effect in the microfibre and macrofibre hybrid systems.

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If of application of the deep deckting floor in long span more than 6m, the deflection caused by the construction load occurred high. Because the constructing-works and safety by this deflection, take actually supports to laborers working on the deck. However, installed supports are having difficultly such as the restricted passage, deficiency of working space, and lowering of efficiency. And toward-opening deck is seen as local buckling of web plate, flexural-torsional buckling, and gradually opening of corrugated decking. In this study, we will suggest a deep decking floor system that reinforced with both ends cap plates for toward-opneing decking change from opening to closing. The constructing deflection of a deep decking more than 6m must be satified 30mm and L/180 as proposed. Full-scale field tests loading by sand conducted a deep decking reinforced with and without cap plate. In conclusion, the specimen reinforced with cap plates have shown that to ensure the negative moment wl 2 /18. And constructing-deflection of deep decking shown that to satisfy the evaluation value (L/180 or 30mm).