Some information was provided about the influence of type and percent of steel and composite reinforcement, on the strength and deformability in strengthened reinforced concrete beams. It was found, that the increment degree of strength in beams decreases by the increasing in percentage of steel reinforcement, especially, when a carbon fiber plastics with hot and cold hardening was used.
Keywords: Concrete, reinforced concrete, steel, composite, the reinforcement rate, the efficiency of strengthening , the varied factors, strength, limit strength, maximum allowable deflection, deformation.
An analysis for the influence, of type and quantity of steel and composite reinforcement, on the normal cracks development, at different load levels, and by the maximum allowable deflection in beams. It was Found that throughout the load range, the reference beams are most cracked. The reduction degree in crack width depends on the strength and percentage of the steel reinforcement.
Keywords: concrete, reinforced concrete, steel, fiberglass, carbon fiber, laminate, maximum allowable crack width, load level, the development of cracks, the relative width
It was provided some information about the character of crack formation and failure of prototypes, which strengthened by three deferent type of composite materials. It was fixed some increased in the crack’s number in beams which reinforced with glass fiber canvas, and 6 deferent mode of failure in strengthened beams.
Keywords: concrete, steel, anchor, composite materials, prototypes, failure modes, load level
Some information was provided about the experimental values of crack width in reinforced concrete beams, which strengthened by three deferent types of glass and carbon fiber reinforced plastics. It was found that, when the strength and modulus of composite are increased, to the width in normal cracks is reduced. Having U-shaped clamps, anchors at the ends of the composite caused a greater reducing in their development. These factors should be considered in theoretical matters.
Keywords: Concrete, reinforced concrete, the reference beams, prototypes, cracks, crack width, the level of the composite reinforcement
An information, is given about the method of strengthening the tested samples by the general requirements of plant’s manufacturer for three types of composite materials. It was presented a dates about the application stages and control of the load intensity
Keywords: Concrete, cement grout, notching, primer, putty, glue composition, stages of loading, the load level indicator, graduation
Provides information about the strength of the concrete, the size of the cross section of experienced beams, the options of their reinforcing and strengthening with various types of composite materials. Provides a scheme of testing with short-term load
Keywords: Steel, concrete, reinforced concrete, strengthening, anchors, span , percentage of steel and composite reinforcement, load, failure
In this article considered the questions related to the possibility of rational use of composite materials in the construction and strengthening of reinforced concrete structures during the reconstruction of buildings and structures. In RSUCE proposed research program which aimed to solving the neglected issues in this direction, and to create a secure calculating apparatus.
Keywords: polymer concrete, epoxy resin, composite materials, fiberglass and carbon plastic reinforcement (GFRP, CFRP rebar), prototypes, research.
In this article considered the questions related to how the deformability is influenced in concrete beams, in which steel reinforcement replaced with fiberglass GFRP or a combination (hybrid). The latter is very important, as the current standards do not account the increased in strength of composite reinforcement, whereas its elasticity modulus is lower than the elasticity modulus of steel reinforcement.
Keywords: concrete, reinforced concrete, strength, deformability, steel, fiberglass reinforcement GFRP, composite, the modulus of elasticity, deflection
Formulating the basic calculating method for reinforced concrete structures based on common physical signs. There are prerequisites for the developed method.
Keywords: reinforced concrete pillar, the method of calculation, stress, Chart Options.
"The results of the computational experiment, Show, that the dependence of the relatively carrying capacity on the relatively eccentricity is almost independent on the reinforcement Ratio or on and concrete type. "
Keywords: High- Strong concrete, self-compacting concrete, modulus of elasticity, column.
Denotes aneedin an engineering analytical correspondence between the loadand longitudinal strains of the composite columns. Experimental data on concrete longitudinal strains in the state of passive lateral compression are presented. The generalized form of correspondence for curvilinear "stress-strain" diagramof concrete the state of passive lateral compression is given.
Keywords: composite columns, "stress-strain"diagram, passive lateral compression of the concrete
The effect of not repeatedly re-exposure to the compressive strength of concrete elements of expanded clay-fiber concrete. The experimental results of reinforced concrete columns after repeated unambiguous and alternating loadings. The influence of repeated loading regimes on the bearing capacity, deformation and fracture of columns. Proposed dependence of the bearing capacity of the columns on the level of repeated loadings.
Keywords: Keramzitofibrobeton, bearing capacity, crack, deformation, reinforced concrete column, mixed reinforcement.
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Statement of the problem. Preparation of high-strength foam concrete in construction allows for energy and resource conservation. Water covers more than 50% of their dense component and on its properties depend strongly on structural properties of foam concrete, is not fully explored.
Results. The effect of mixing water of low temperature on the structure and properties of constructive penofibrobetonov. Recommendations on the account in the calculation of reinforced concrete elements elevated structural properties and deformation diagrams penofibrobetonov by mixing water setback.
Conclusions. Using low temperature mixing water improves the structure, increases the strength, deformability and elastic modulus, as well as changes of the deformation diagram fibropenobetonov.
Keywords: fibropenobetona, foam, water temperature mixing, macroporosity, economic efficiency, technical and economic assessment.
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The influence of non-multi - repeated loads on columns of keramzito fibrobetona. Comparative results of tests Depends on the flexibility of columns, the eccentricity of the external force, the coefficient of reinforcement options and loading. The obtained results suggest that repeated loading nemnogokratno increase the carrying capacity of columns, compared with a single loading. This is especially effective for columns with low flexibility and small eccentricities external force.
Keywords: stand, keramzitofibrozhelezobeton, bearing capacity, nemnogokratno repeated loading, mixed reinforcement flexibility.
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Information about authors of issue №1 (2012)
Keywords: authors