Improving the reliability and durability of sidewalks, footways, car parks and areas for various purposes, made of concrete paving blocks (CPBs), is an important task of construction. In order to improve the quality characteristics, new pavements consisting of concrete paving blocks with a ribbed underside surface are proposed. Hypotheses about the advantages of the developed structural solutions of pavements relative to traditional pavements of blocks with a flat underside surface were formulated. To confirm the hypotheses, studies of one of the developed pavement variants of in laboratory conditions were performed. The article describes the plan and methodology for implementation two series of experiments. In the first series of the experiment, a section of a traditional pavement of concrete blocks with a flat underside surface was investigated, in the second, a section from a pavement of concrete paving blocks with a ribbed underside surface consisting of three prismatic elements. Qualitative characteristics of the pavement are determined by various indexes. As a result of laboratory tests, the dynamics of settlement of experimental CPBs under the influence of vertically applied load was studied, and density index of a sand structural layer located under the tested CPBs was also obtained. The settlement indexes of the tested CPBs were investigated for three days. A comparative analysis of the experimental results confirmed the hypothesis about the advantages of pavements of concrete paving blocks with a ribbed underside surface. For the further implementation of the developed pavement variant in the construction industry, additional research is required. Further research directions of pavements of concrete paving blocks with a modified geometric shape of the underside surface are determined.

Annotation Purpose. Establishment of the relationship between the deformation of the blade parts of tillage and design parameters after electro arc. Methods. Planning an experiment, mathematical statistics and analytical processing of experimental data. Results. The dependences of the deformation of the blade parts of tillage equipment on the design parameters after their recovery and hardening by electro arc are established. Conclusions 1. It has been established that the magnitude of the deformation Δ, mm of the part of tillage, is inversely depends on the thickness δ after hardening. 2. It has been established that the magnitude of the deformation Δ, mm of the part of tillage, is inversely dependent on the width B after hardening. 3. The rational modes of electro arc were established when hardening parts of tillage with a thickness of 4–10 mm, a width of 20 mm to 60 mm and a length of 230 mm to 500 mm, namely, a current of 350–400 A, a voltage of 50–55 V and a temperature cooling medium in the bath of the installation for simultaneous electro arc sharpening and hardening – 20–60 °С. Such rational modes of electro arc ensure the absence of deformation of parts of tillage less than 5 mm, which is permissible according to the requirements of regulatory, technical and design documentation. Keywords: deformation, length, operation, electro arc, hardening, parts of tillage, thickness, width.

Національний науковий центр «Інститут механізації та електрифікації сільського господарства», Україна. Стаття з спеціальності: 133-галузеве машинобудування.

Purpose. The researched of the wear resistance of hardened plowshares by electroarc and abrasion-resistant electrodes, when they are used in soils of different types. Methods. Conducting and planning an experiment, mathematical statistics and analytical processing of experimental data, field tests of experimental plowshares using the basic principles of the theory of friction and abrasive wear. Results. The characteristic defects of shares operating in different types of soils are determined. According to the proposed hardening technology, the wear rate of experimental shares is reduced. Conclusions 1.It has been established that the nature of the parts of tillage machines wear is significantly different when operating on various types of soils. 2.It was found that the wear rate of hardened plowshares for sandy soils is 1.2–1.6 times less than that of serial parts; hardened plowshares for clay soils also have a wear rate of 1.2–1.3 times less than serial ones. Keywords: exploitation, hardfacing, plowshares, soils of different types, wear, wear resistance.

Purpose. Reducing the cost of technological operations for tillage due to increased resource cultivator paws. Methods. Monographic, mathematical-statistical, economic-mathematical, graphic-analytical. Results. The methodical approach to determining the economic efficiency of local hardening of cultivator paws using wear-resistant powder material with the aim of increasing the resource is substantiated. The limits of increasing the resource of cultivator paws KPE-410 and the maximum value of the cost of its hardening for the effective functioning of industrial enterprises are substantiated. Conclusions. The effectiveness of local hardening of the cultivator paw KPE-410 using wear-resistant powder material is achieved under the condition that the resource of the hardened cultivator paw is more than 18.7% of the serial sample. Provided that the resource of the strengthened cultivar's paw is 37% of the serial, in order to ensure efficiency, the cost price of hardening of one cultivar's foot KPE-410 should not exceed 112.5 UAH. It was established that with the cost of hardening of the cultivar leg Sz = 53.77 UAH and its resource 55 hectares, the economic efficiency is 109%. Keywords: efficiency, local strengthening, resource, working bodies of tillage machines, cost of hardening.