Within the framework of this article, experimental studies of concrete reinforced with polypropylene fiber of two geometric dimensions of 6 mm and 12 mm are presented. Studies were carried out on samples of cubes 10 × 10 × 10 cm and samples of prisms 10 × 10 × 40 cm. In total, more than 100 samples were tested. The objectives of the experimental study: testing fiber concrete samples for compression, analyzing the results obtained, identifying changes in strength and deformation characteristics as a result of fiber reinforcement. Tests of the samples showed an increase in strength of up to 20%, as well as the effect of the percentage of fiber reinforcement on strength properties. The limit percentage of fiber reinforcement was determined, when exceeding which a decrease in strength properties occurs

Keywords: polyarmoured fibre concrete, fibre concrete, low-modulus fibre, polypropylene, strength properties

Based on the results of experimental studies of the propagation of bending waves, the ability of the developed technique to assess the strength of a brick treasure is considered. A comparative analysis of the strength of the masonry was carried out using different methods (L.I. Onishchik formula, Eurocode 6). According to the correlation dependencies between the velocity of propa-gation of elastic waves and the strength of masonry, the presented practical data made it possible to prospectively evaluate the method using bending waves in the survey of buildings and struc-tures.

Keywords: experimental studies, brickwork, elastic waves, bending wave velocity, strength