EFFECTS OF HYBRID FIBRES ON THE PROPERTIES OF FIBER-REINFORCED CONCRETE

摘要

Hybrid fibre-reinforced concrete is a type of fibre-reinforced concrete characterised by its composition. Specifically, it contains at least two or more types of fibres of different sizes, shapes or origins. It is well known that cracking in fresh concrete can be effectively inhibited by polypropylene fibres and that different sizes of steel fibres contribute to different mechanical properties. For this reason, three types of steel fibres and two types of polypropylene fibres were used in experiments. Mechanical properties (compressive, flexural and splitting strengths, modulus of elasticity, toughness) and durability properties (gas permeability, water absorption) were measured. The test results were analysed statistically according to a single factor model of analysis of variance. The analysis of the results, obtained for the said properties of hybrid and plain fibre-reinforced concretes in hardened state, includes the comparison of those concrete types and the influence of kinds and amounts of polypropylene and steel fibres used and silica fume admixed on particular properties tested. These results showed the advantages of the use of hybrid fibres in fibre-reinforced concrete.