scholarly journals Experimental and theoretical studies of biaxially prestressed steel-fiber-concrete slabs.

2018 ◽  
Vol 2 (3) ◽  
pp. 10-14
Author(s):  
Oleksandr Zhuravskyi ◽  
Andriy Gorobetc
Keyword(s):  
Steel Fiber ◽  
Physical Nonlinearity ◽  
Concrete Slabs ◽  
Theoretical Studies ◽  
Transverse Loading ◽  
Software Complex ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
Experimental And Theoretical Studies

The article presents the results of experimental and theoretical studies of strength and deformability of steel-fiber concrete double-sided pre-stress slabs under the action of transverse loading. The simulation of such plates in the software complex LIRA-SAPR was performed taking into account the physical nonlinearity of materials.

scholarly journals Comparative analysis of strength and deformation of reinforced concrete and steel fiber concrete slabs

2020 ◽  
Vol 166 ◽  
pp. 06003
Author(s):  
Mykola Surianinov ◽  
Stepan Neutov ◽  
Iryna Korneieva
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Bearing Capacity ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Experimental Studies ◽  
Concrete Slabs ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
The Moment

The results of experimental studies of the steel fiber influence on the bearing capacity, deformability and crack resistance of reinforced concrete multi-hollow plates are given. We investigated a serial floor slab and a similar one, but with the addition of steel fiber. Both plates are factory-made. For testing, the testing apparatus was designed and manufactured that made it possible to study full-size floor slabs in laboratory conditions. The tests were carried out according to a single-span scheme with the replacing equivalent load. The loading was carried out by applying two concentrated strip vertical loads along the plate width. The load was applied in steps of (0.04 ÷ 0.05) from the breaking load. Each stage ended with exposure lasting up to 10 minutes with fixing all the necessary parameters. Deformations were measured using dial gauges. From the moment the first crack appeared in the stretched zone of concrete, the process of crack formation and opening was monitored. At each level, using the Brunell tube, the width of their opening and height were measured. The moment of cracking in both slabs began at the same relative strain. It has been established that the bearing capacity and crack resistance of a slab of combined reinforcement using steel fiber are respectively 50 and 44% higher than that of a similar reinforced concrete slab. The maximum deflection of the slab of combined reinforcement is 37.5% lower than that of conventional reinforced concrete. The destruction of both slabs occurred under loads, when the relative deformations in the compressed zone of concrete reached 0.80×10-3 and 1.10×10-3 for reinforced concrete and steel-fiber concrete slabs, respectively, the difference is 37.5%.

scholarly journals Bearing capacity of steel-fiber-concrete slabs with biaxially prestressed reinforcement

2020 ◽  
pp. 292-301
Author(s):  
Oleksandr Zhuravskyi
Keyword(s):  
Bearing Capacity ◽  
Steel Fiber ◽  
Experimental Studies ◽  
Biaxial Compression ◽  
Concrete Slabs ◽  
Deformation Method ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
The Difference ◽  
Prestressed Reinforcement

The aim of the research is to obtain new experimental data of biaxially prestressed steel-fiber-concrete slabs under transverse loading and to develop a method for calculating their bearing capacity. Experimental-theoretical studies of biaxially prestressed steel-fiber-concrete slabs under the action of a uniformly distributed load were performed. Experimental studies were performed on plates measuring 40x800x800 mm with prestressed reinforcement Ø5Bp-II in two directions. Samples of the first series were reinforced with a mixture of steel fibers of STAFIB 50/1.0 and STAFIB 30/0.6 with anchors at the ends, the percentage of which was 0.5% by volume of each fiber. The samples of the second series contained 1.0% by volume of NOVOKON URW 50/1.0 corrugated fibers. A method for calculating steel-fiber-concrete (SFB) slabs based on the deformation method is proposed. This takes into account the real diagram "σ-ε" for uniaxial and biaxial compression of steel-fiber-concrete and increase the compressive strength of steel-fiber-concrete under conditions of biaxial compression. Stress losses in the reinforcement from creep and shrinkage deformations of steel-fiber-concrete are also taken into account. The results of calculation of experimental samples and their comparison with the results of experimental researches are given. They showed sufficient convergence. The difference was 1.1… 2.5%. It is established that the bearing capacity of biaxially prestressed slabs is 1.55… 1.61 times higher than unstressed slabs and 42.4… 55.5% higher than uniaxially stressed slabs.

scholarly journals ПРОЕКТИРОВАНИЕ И ЭКСПЕРИМЕНТАЛЬНЫЕ ИССЛЕДОВАНИЯ СТАЛЕФИБРОБЕТОННОЙ ПЛИТЫ ПЕРЕКРЫТИЯ

World Science ◽  
2018 ◽  
pp. 28-32
Author(s):  
Сурьянинов Н. Г. ◽  
Корнеева И. Б.
Keyword(s):  
Crack Resistance ◽  
Bearing Capacity ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Concrete Slabs ◽  
Fiber Concrete ◽  
Steel Fiber Concrete ◽  
Control Load

In the work, the design of the floor slab with five voids of steel fiber concrete, similar to a serial reinforced concrete slab, is proposed. Both plates are calculated in accordance with the regulations on the first and second limiting states. For experimental studies, a series of plates was made, each of which was tested before destruction. Scaling was used for all the plates, taking into account the design standards and technological capabilities of the laboratory.The loading of structures during testing was carried out in steps. Each step was 10% of the control load when checking the bearing capacity and crack resistance and 20% of the control load when checking the rigidity of structures. As a result of tests, the values of stresses and deflections were obtained as in theoretical calculations, the stresses in the concrete and steel fiber concrete slabs differ only slightly, and the deflections, especially up to 60% of the breaking load, differ several times, which confirms the much slower crack opening in the steel fiber concrete slabs. This suggests that at loads corresponding to the operational level, cracks will not open. The use of steel fiber concrete with preservation of linear reinforcement for the manufacture of hollow-core slabs allows to improve their characteristics, first of all - bearing capacity and crack resistance.

scholarly journals DEFORMABILITY AND CRACK RESISTANCE OF AIRFIELD SLABS

2021 ◽  
pp. 52-61
Author(s):  
M.G. Surianinov ◽  
◽  
S.P. Neutov ◽  
I.B. Korneeva ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Crack Resistance ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Crack Opening ◽  
Experimental Studies ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Fiber Concrete ◽  
Steel Fiber Concrete

Abstract. The results of experimental studies of deformability and crack resistance of models of airfield slabs made of reinforced concrete and steel fiber concrete are presented. Two series of plates were tested ‒ three models of reinforced concrete and three models with steel fiber added to the concrete mixture in amount of 1% of the total volume of the product. The load was applied in small steps, the instrument readings were recorded twice at each step, and the crack opening width was measured starting from the moment of the first crack formation. Dial gauges and deflectometers were used as measuring instruments. According to the normative documents acting in Ukraine, one of two possible loading schemes was considered ‒ with the loading by the concentrated force applied on the cantilever part of a plate. The plate models were tested on a specially made stand which consisted of four supporting struts connected in pairs by beams. The airfield slab was supported by the beams. The load was applied along the width of the plate in steps ‒ 0.05 of the destructive load, along two concentrated vertical strips. Each degree of load ended with a five-minute dwell time, at the beginning and end of which readings were taken on the measuring instruments. The deformations at the same levels were measured with dial gauges. The process of crack formation was observed with a Brinell tube in the places of the greatest crack opening. It follows from the obtained results that the process of cracking in the fiber concrete slab begins at higher loads than in the reinforced concrete slab. The final and initial crack opening widths of all cracks in the fiber concrete slab are significantly lower than in the reinforced concrete slab. The deformations in steel-fiber concrete slabs during the application of load in the cantilever part, both for compressed and stretched fibers are higher than in reinforced concrete slabs. At the initial stages of load application in the cantilevered part of the slabs, the deflections increase in a linear relationship. The curves get non-linear character for airfield slabs made of reinforced concrete when the load reaches the level of 10÷25 kN, for steel-fiber-concrete slabs ‒ 15÷30 kN. In reinforced concrete slabs, the non-linearity starts a little earlier and is expressed more clearly. Experimental studies show that dispersed reinforcement of airfield slabs with steel fiber leads to their higher crack resistance.

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