The authors present the results of RD on the topic of coupling slip of threadbar of class Av500P. The aim of the work was to obtain experimental data to study the effect of the threadbar coupling on the slip (deformability) of the joint and taking into account the characteristics of the joint in the design of structures. The strength and deformability of coupling samples of threadbar with a diameter of 16, 25 and 40 mm with an innovative four-sided (four-row) thread profile of class Av500P have been studied in accordance with the methodology of international and Russian standards. The samples were made with different tightening torques of the lock nuts and anchor-adhesive compositions inside the coupling. Along with the results of the study, it can be concluded that these couplings of innovative four-row threadbar of class Av500P meet the requirements of international and Russian standards when applying a certain tightening torque to the tightened lock nuts, depending on the diameter of the fittings to be joined and the use of anchor-adhesive compositions on large and medium diameters of the threadbar to be joined. The diagrams of thread joints obtained during the experiment can be used in design practice when design reinforced concrete structures according to the deformation model. Together, this makes it possible to introduce thread joints into the Russian construction regulatory code.

Article provides an overview of the world and domestic samples of high-strength threaded rebar for pre-stress in concrete structures. First of all, their technical characteristics were analyzed that affect the speed of installation of buildings and structures and the metal content of reinforced concrete structures used in them. We also consider the individual characteristics of the profile of rebar that are specific to individual countries, followed by an assessment of their behavior in reinforced concrete structures. Special attention is paid to domestic developments in this direction, in order to assess the competitiveness of innovative profiles both within Russia and on the world market. One of the most important developments in recent years in our country is the rebar class Av1000P, the history of which described in the second chapter of this review. The reason for the development of this profile was significant problems related to the crack resistance, thrust and endurance of previous types of thread and periodic profiles of high-strength rebar products. In addition to the reinforcement profiles, a high-speed method of joining and anchoring with the help of coupling threaded connections was partially considered, which is only possible on a screw profile armature without labor-intensive threading on rods.

This article discusses the background and history of the emergence of innovative, popular today, types of rebar for construction, their distinctive features and quality indicators, the methodology and results of various studies conducted on the basis of NIIZHB named after A.A. Gvozdev of JSC Research Center of Construction and LLC Technological Institute VNIIzhelezobeton . The purpose of this article is to introduce new types of innovative rebar products and demonstrate their advantages. For the tests, the results and methods of which are given in the article, test rolls of rebar with a four-row screw profile were made. In terms of strength and deformability of adhesion to concrete, the reinforcement with multi-row (four-row and six-row) reinforcement profiles significantly surpassed the reinforcement with two-row crescent (European) and screw (GEWI-Stahl analog) profiles. It has demonstrated high adhesion to concrete not only in the operational, but also in the extreme stage of deformation of the reinforcement. This article discusses the background and history of the emergence of innovative, popular today, types of rebar for construction, their distinctive features and quality indicators, the methodology and results of various studies conducted on the basis of NIIZHB named after A.A. Gvozdev of JSC Research Center of Construction and LLC Technological Institute VNIIzhelezobeton . The purpose of this article is to introduce new types of innovative rebar products and demonstrate their advantages. For the tests, the results and methods of which are given in the article, test rolls of rebar with a four-row screw profile were made. In terms of strength and deformability of adhesion to concrete, the reinforcement with multi-row (four-row and six-row) reinforcement profiles significantly surpassed the reinforcement with two-row crescent (European) and screw (GEWI-Stahl analog) profiles. It has demonstrated high adhesion to concrete not only in the operational, but also in the extreme stage of deformation of the reinforcement.

The ability of concrete to give a lower weight and retain good properties for strength is very important concrete structures. Lightweight concrete is known for its brittleness hence the strengthening of the concrete with dispersed chopped fiber is necessary. The addition of dispersed chopped fiber in polystyrene concrete to check the effect of the fiber this concrete the main objective of this paper. The experimental method of research was used in this research paper after a proper review of previous works by other researchers were done. 42 grams of fiber were added in the concrete mix of each composition. The results of this research show a noticeable effect of fiber in the lightweight expanded polystyrene concrete. The concrete without fiber showed the best compressive strength followed by the concrete with dispersed polypropylene fiber.

The results of the analysis of the efficiency of the functioning of small enterprises in the construction market of Jordan are presented. The peculiarities and significance of the work of small enterprises in the economic sphere of the country are revealed. It is shown that the development of small and medium business in Jordan as a whole does not differ from the similar situation in other countries. This is due to the specifics of the processes of globalization of the economy.