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Inthis paper, we report the results of our research on reinforced concrete beams made of fine aggregate fibre composite, with the addition of steel fibres at 1.2% of the composite volume. The fine aggregate fibre composite is a novel construction material, in which the aggregate used is a post-production waste. Twenty reinforced concrete beams with varying degree of shear reinforcement, in the form of stirrups with and without the addition of steel fibres, tested under loading. The shear capacity results of reinforced concrete beams made of the fine aggregate fibre composite being bent by a transversal force, as well as the cracking forces causing the appearance of the first diagonal crack, are discussed. The stages of functioning of such elements are described. Furthermore, the effect of the steel fibres on the reduction of diagonal cracking is analysed. Computation of the shear capacity of the tested elements is performed, based on the Model Code 2010 and RILEM TC-162 TDF standards, for two variants of the compression strut inclination angle θ that measured during testing, and the minimum(in accordance with the Model Code 2010 standard). We found that the SMCFT method part of Model Code 2010 showed the best compatibility with the experimental results. The tests and analyses performed demonstrate that the developed novel fibrecomposite—the properties of which are close to, or better than, those of the ordinary concrete—can be used successfully for the manufacturing of construction elements in the shear capacity aspect. The developed fine aggregate fibrecomposite could serve, in some applications, as an alternative to ordinary concrete.

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The paper proposes a method of estimating the properties of a fine aggregate steel fibre reinforced cementitious composite using non-destructive methods. Two methods were selected to identify the properties of such a composite. One of them uses electromagnetic induction in order to estimate the content of steel fibres dispersed in the composite space, while the other is based on the determination of ultrasonic wave velocity propagating through the composite. Having defined correlations between the properties of the fibre reinforced composite and non-destructive testing parameters, regression equations were determined. Seven relationships between properties of fibre reinforced composite as the dependent variables and two independent variables, i.e.: amperage and ultrasonic wave velocity, were established. Knowing the amperage and the ultrasonic wave velocity, the basic properties of the fibre reinforced composite can be determined from the regression equations in a non-destructive manner. In order to verify the equations, three plates with different amounts of steel fibres were made in field under natural conditions, and next subjected to non-destructive tests. The tests showed good compatibility between the experimental results and those of calculations, which indicates the correctness of the formulated equations.