This article deals with the introduction of reinforced concrete structures with a variable pre-stress combined along the span. The identification of economic efficiency from replacement of reinforcement and prestressing is carried out.
Keywords: concrete, reinforced concrete, structures, technologies, installation, reinforced concrete structures, tension, prestress, beams, reinforcement, efficiency
Presented the general selection of external composite strengthening, based on the use of the above characteristics of the materials for the strengthened elements of the rectangular profile.
Keywords: concrete, reinforced concrete, composite strenghtening, steel, calculation method, strength, capacity
Have been given the substantiation of the need for preliminary testing of concrete beams on the transverse force. Their goal is to determine the effect of inclined cracks formed at the operating load levels, on the efficiency of the composite reinforcement in the near support sections. The results of these tests, obtained with the shear span 1,5h0; 2h0 and 2,5 h0, that significantly affects the nature of inclined cracks. According to the results of an experiment formulated recommendations for the design of composite reinforcement.
Keywords: concrete, reinfrcement, reinforced concrete composite, CFRP, strengthening, crack, stress level, clamp, shear span, strength
The article is concerned with development of optimal reinforcement constructions of hollow-core slabs to ensure reliable recovery or increase the bearing capacity, safe operation of hollow-core slabs, safety operation of hollow-core slabs, cost and complexity inimisatrion.
Keywords: Hollow-core slab, reinforcement construction, optimization, safe operation, reinforcement, plot points, plot materials, rod, the center of gravity of the reinforcement
There are new options of reinforcement hollow core slab. The essence of the proposed solutions is to install the rod into the groove located below the voids of the slab. Describes the field of rational use, as well as design and fabrication of these options of reinforcement.
Keywords: reinforcement of building constructions, safety operation, hollow core slab, normal section
Presented and analyzed the data of the test results of concrete columns with the flexibility of λh=10 and λh=20, the strengthening of the external carbon fiber reinforcement. Borders impact of the various options strengthen influence on strength and deformability of columns and efficiency of composite materials installed.
Keywords: concrete, reinforcement, reinforced concrete composite, eccentricity, flexibility, capacity, strength, deformability, strengthening
The data on the bearing capacity of short reinforced concrete columns with the flexibility λh = 10 strengthened by CFRP, the action of axial load, eccentricity e0 = 4cm. Effectiveness of various options for strengthening was determined, provided the action force outside core-section.
Keywords: concrete, reinforced concrete, steel, rebar, composite, carbon fiber, strength, load-bearing capacity.
Presented and analyzed data on the results of tests of short reinforced concrete columns with the flexibility λh = 10 strengthened by CFRP for external applying force with an eccentricity e0 = 2 cm. The effect of strengthening on the bearing capacity and deformability of columns when a load is applied to the inside of the core-section.
Keywords: concrete, reinforced concrete, reinforcement, CFRP, load, strength, deformability.
The most promising technologies of concrete and reinforced concrete for the underground construction and transport. The studies with the inclusion of concrete and steel and polypropylene fibers. The factors affecting the strength and modulus of deformation materials. The conclusion about the need to study the effectiveness of the concrete with a combined reinforcement.
Keywords: Concrete and underground construction, fiber, strength, modulus of deformation
The article describes the experience of the unique complex of works to improve the operational reliability of the emergency office buildings located in a cramped building, whose main task was to eliminate excessive rolls with hydraulic jacks and ensure the continued trouble-free operation. Highlighted the key features of the design and technology solutions for the simultaneous lifting and leveling of several buildings with different design decisions.
Keywords: adjustable foundation, electro-hydraulic flat jacks, cramped building, lifting and leveling, operational reliability.
Management can be performed on the principles of motivation, planning, regulation of the course of production, coordination, organization and control on execution of decisions. Operate and develop the production units, depending on the goals
Keywords: structure, management, goal, head, processes, organisation.
This article is devoted to the consideration of economic, social and urban effect in the co-production work on the laying of utilities. The main results of evaluation of the economic efficiency of the options considered gasket types of utilities.
Keywords: efficiency, design, evaluation, variance, network engineering, installation
This article provides an account tsentrenno and eccentrically compressed reinforced concrete columns of high-strength concrete on the deformed pattern in SP 63.13330.2012. Compares the results of the calculation of the bearing capacity of the columns with the set experimental data. Proposed adjustments in the form of the coefficients in the formulas for the curvature tsentrenno compressed columns j and eccentrically compressed yb.
Keywords: high-strength concrete, physical experiment, prism strength, lateral reinforcement, concrete counters, deformation correction factor
In article the direct connection of a condition of soils and quality of a formed superficial diffusion drain is considered. For minimization of pollution of a superficial drain and ground waters when unloading them in a reservoir it is offered to use coal mining waste as a sorbent of organic and inorganic pollution. Thus, the area of utilization of dump breeds of coal mines for nature protection and soil-improving actions extends.
Keywords: Dump breeds of coal mines; sorbent; minimization of pollution of a superficial drain; the urbanized territories; anthropogenous impact on the soil
2-D and 3-D problems of the elasticity problems for incompressible materials are considered. Solving these problems using the finite-element method results in solving the linear algebraic equations system with sparse matrix. For incompressible materials this system is the system with a saddle point (i.e. the matrix eigen values have different signs). Thus, applying such solving methods as the conjugate gradient method and the generalized minimal residual method is impossible. Uzawa method is suggested to be used for such problems. It is an iterative process, and at each iteration it is necessary to solve the linear algebraic equations system, but this system is without a saddle point. The different variants of Uzawa algorithm are realized within CAE Fidesys software package, and their efficiency is compared in the article.
Keywords: theory of elasticity, incompressible materials, finite-element method, Uzawa algorithm, iteration methods for systems of linear algebraic equations