The use of concrete with traditional reinforcement pose the problem of finding ways to increase the crack resistance, impact strength, frost resistance and other characteristics, which in turn depend on the strength properties of the material. One of the solution is the use of dispersion reinforced concrete steel fiber concrete (with short steel fibers of 30-50mm). The combination of rigid fibers with significant strength reserves and the concrete could increase the crack resistance of the matrix and other strength characteristics. The paper presents the results of theoretical studies of the reinforcement percentage effect on the stress-strain state of the rectangular cross-section elements of steel fiber reinforced concrete (SFRC) in bending from at repeated loads with levels of application η = 0.5 and η = 0.7 . It is found that the limit deformations of the SFRC cross-section in bending is recommended to calculate using a polynomial function, which gives the greatest convergence between the true values and approximations in comparison with the logarithmic and exponential functions.

Recently, environmental problems have become more acute. In 1980, the International Union for the Conservation of Nature (IUCN) prepared the World Conservation Strategy. This document interpreted the term "sustainable development" as an inseparable link between social development and nature conservation. And already in 1992, after the United Nations Conference on Environment and Development, the concept of sustainable development gained a leading status. The conference materials determined that sustainable development is a development of a society that meets the needs of today without compromising the ability of future generations to meet their own needs. Therefore, being aware of the need for energy conservation, there is increasing emphasis on the use of solar energy throughout the world to generate electricity and heat.

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Abstract. The drainage system is one of the components of the road design. The condition of the subgrade and pavement depends on its effectiveness. The main structural elements of the drainage system on the roads are gutters and pipes. They are made of concrete or reinforced concrete. Under the influence of climatic factors and fluctuations of the vibration caused by the vehicles movement on the surface, it occurs destruction: formation of cracks, potholes, husking of concrete, destruction of protective layer of concrete, etc. It should be noted that these structures perceive the dynamic and thermal effects. The low fracture materials toughness poses the issue of searching ways of its increase. One solution of this problem is the use of dispersion-reinforced concrete gutters and pipes. The article presents the results of research strength, crack resistance and deformability of gutters and pipes using steel fiber reinforced concrete under the action of repeated loads Non-pressure pipes and street gutters on the roads used in the construction of drainage systems for drainage of rain, snowmelt and groundwater from road sections with a high degree of load, highways, walkways, airports and terminals. It should be noted that future traffic on the roads I-A and I-B categories, according to calculations takes more than 10000 vehicles per day. The throughput of an individual vehicles of Ukraine even exceed these standards, in particular, the highway Kyiv-Boryspil traffic is about 40 thousand vehicles per day. A huge stream of traffic through the cross section of a road of this class creates significant dynamic vibration oscillations, which act on road transport facilities. While the low fracture toughness of the materials of gutters and pipes puts the issue of finding ways to improve it.One solution in this direction is using of concrete in these construction of gutters and pipes with the addition of reinforcing elements looks like a short steel cuts -steel fiber reinforced concrete. The combination of rigid (and because of this with considerable reserves of strength) fibers with the matrix (concrete) allows to localize the danger associated with brittle destruction of the matrix and to realize the basic properties of fibers: greater potential tensile strength and high modulus of elasticity.

Experimental research of new materials and structures with improved parameters of strength, fracture toughness, bearing capacity and their lifetime in comparison with typical elements is an actual problem of building science.Nowadays there is a trend to design and use for buildings covering the new design solutions as the thin shells. One of the types of thin shells are Gaussian shells with negative curvature. It’s worth to note that in the last decade, a considerable number of researches of thin-walled structures made of steel fiber reinforced concrete were conducted, which confirmed the efficiency of its use to enhance their hardness, fracture toughness and thus longer life.The article presents the results of the authors’ experimental studies of fracture toughness of thin-walled cover structures with Gaussian negative curvature in the shape of hyperbolic paraboloid made of ferrocement and steel fiber reinforced concrete under the action of the operating load.The load application was carried out for ten steps, after each step the pause was for 15...20 min, during which the data of the strain-gauge station VNP-8 was recorded, using a microscope were measured and recorded the width of the cracks, deflections of the structure were measured etc.The external force was evenly-distributed to its applications and the impact was simulated according to the real conditions of construction use.The experimental part of the research was conducted at the laboratory of building materials and structures of Lutsk National Technical University. In scientific work carried out mapping and comparison of the obtained experimental results, carried out processing and analysis, presents the conclusions.During the researches it was found that the fracture toughness of thin-walled shell cover with Gaussian negative curvature in the shape of a hyperbolic paraboloid with dispersed reinforcement (steel fiber reinforced concrete) is higher than in the shell made of ferrocement. Accordingly, it can be argued about the increasing of the lifetime of steel fiber reinforced concrete shell covering in comparison with the ferrocement shell.