Steel fiber reinforced concretes are currently very popular, especially in the construction of industrial floors of warehouses and other halls with relatively large floor areas. However, it is important to mention that despite the rapid development of steel fiber reinforced concretes, the standards and regulations for their designing and testing have not been unified yet. This paper presents findings about the physicomechanical parameters of the steel fiber reinforced concretes manufactured by adding steel fibers into the truck mixer on the building site. The experimentally obtained results from the performed tests of tensile strength in bending according to various procedures are compared, and the suitability of the methods used is assessed according to these procedures.

The paper reacts to the contemporary situation in the field of determining the position of reinforcement in the reinforced concrete structures, in which the best method used so far – the Co 60 radiography – is significantly limited or even excluded due to the tightening of laws and regulations for management of radiation sources. In the article, the authors focus on the use of alternative NDT methods which, in an appropriate combination, can substitute the present radiographic method. They mention the advantages as well as technological and principle limitations of the methods of georadar and electromagnetic indicators, and on practical examples they demonstrate their usability when used separately or in a suitable combination.

Many research teams currently deal with the issue of determining the distribution of steel fibres in the hardened steel fibre reinforced concrete, both in terms of fibre concentration, and in terms of homogeneity of fibre distribution in the concrete. The basic element in the development of new non-destructive methods is the development of new principles and devices on adequate test specimens, in which precise spacial distribution of fibres, including the orientation of individual fibres, would be quite evident. The paper presents two technologically completely different possibilitites of dealing with this issue. X-ray radiography is a traditional and long-established method, but in the field of construction, the authors' workplace is one of the few in the Czech Republic able to use it. The method of creating transparent specimens is completely unique, as it has been developed and is used only at the authors' workplace.

Correct reinforcement is an essential part of constructing reinforced concrete structures. Errors in positioning, diameter, or coverage may result in defects, which is why it is necessary to make sure the reinforcement is implemented well. Even though electromagnetic detection is the most common non-destructive method for locating reinforcement in reinforced concrete, science literary sources hardly discuss it. The main reason is a lack of graphic test results – thus far the most common research outcomes have been photographs of lines drawn on the concrete surface or additions to technical drawings of the reinforcement. Only modern detectors expanded the possibilities of the method's application including graphic measurement records and a more accurate estimation of reinforcement diameter including corrections for adjacent reinforcement spacing. The paper focuses on the principle of measurement and practical examples of determining the position and coverage of reinforcement in reinforced-concrete structures using a state-of-the-art electromagnetic rebar detector – a Profometer PM-630. Aside from data recording and statistical evaluation during coverage measurement, modern instruments also allow the data to be exported and visualised.