scholarly journals Ductility and flexure of lightweight expanded clay basalt fiber reinforced concrete slab

2021 ◽  
Vol 17 (1) ◽  
pp. 74-81
Author(s):  
Vera V. Galishnikova ◽  
Alireza Heidari ◽  
Paschal C. Chiadighikaobi ◽  
Adegoke Adedapo Muritala ◽  
Dafe Aniekan Emiri
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Lightweight Aggregate Concrete ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Chopped Basalt Fiber

Relevance. The load on a reinforced concrete slab with high strength lightweight aggregate concrete leads to increased brittleness and contributes to large deflection or flexure of slabs. The addition of fibers to the concrete mix can improve its mechanical properties including flexure, deformation, toughness, ductility, and cracks. The aims of this work are to investigate the flexure and ductility of lightweight expanded clay concrete slabs reinforced with basalt fiber polymers, and to check the effects of basalt fiber mesh on the ductility and flexure. Methods. The ductility and flexural/deflection tests were done on nine engineered cementitious composite (expanded clay concrete) slabs with dimensions length 1500 mm, width 500 mm, thickness 65 mm. These nine slabs are divided in three reinforcement methods types: three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm (first slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed chopped basalt fiber plus basalt fiber polymer (mesh) of cells 2525 mm (second slab type); three lightweight expanded clay concrete slab reinforced with basalt rebars 10 mm plus dispersed basalt fiber of length 20 mm, diameter 15 m (third slab type). The results obtained showed physical deflection of the three types of slab with cracks. The maximum flexural load for first slab type is 16.2 KN with 8,075 mm deflection, second slab type is 24.7 KN with 17,26 mm deflection and third slab type 3 is 32 KN with 15,29 mm deflection. The ductility of the concrete slab improved with the addition of dispersed chopped basalt fiber and basalt mesh.

scholarly journals Reconstruction of an arched metal bridge over the Kineshemka River in the city of Kineshma, Ivanovo Region

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Vilgelm Kazaryan ◽  
Inna Sakharova
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
High Strength ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Main Beam ◽  
Acceptance Testing ◽  
Main Task ◽  
Reinforced Concrete Slab ◽  
Main Metal

This article discusses the technology of reconstruction of a metal arch bridge by reinforcing the structure with prestressed elements. The main metal beams were in unsatisfactory condition, the metal structures of the span below the level of the roadway slab are subject to deep layered corrosion up to the formation of through damage. To restore the bearing capacity of the main beams of the Nikolsky bridge across the Kineshemka river, their reinforcement is provided. The main task when performing the reinforcement of the main beams is the installation of new prestressed reinforced concrete beams directly inside the old metal main beams of the bridge with the regulation of forces in high-strength ropes. Due to the fact that the effort of high-strength ropes cannot be immediately brought to maximum design loads, a step-by-step prestressing scheme of ropes with synchronous sectional concreting of main beam compartments is proposed. The process of tension in the reinforced concrete beam of the main beams is carried out in two stages: stress at the end sections, where an anchoring system was created in four corners and then prestressing the main gift space with concreting sections between the pendants according to a specially developed scheme in the work design. Only fiber-reinforced concrete is used, and reinforcing stops were welded to work together with the inner surface of the main beams. Examples of reinforcing steel beams with steel strands on steel-reinforced concrete spans already existed, however, the transfer of force through a reinforced concrete inner beam was carried out for the first time in the world. After the main tie-in beams began to work together with a metal arch, it was decided to start repairing the cross-beams, which hold the reinforced concrete slab in the longitudinal direction, and themselves rely on the main beams. Some transverse beams were corroded to the point that they were holding onto a reinforced concrete slab, therefore NPP SK MOST developed a technology for prestressing the transverse beams with their jacking and subsequent shotcreting from all sides, and they were supported on the main beams, which were already ready for perception load. In conclusion, the authors confirm the effectiveness of the proposed technology; At the end of 2018, an examination and acceptance testing of the Nikolsky Bridge was carried out. The results of static and dynamic tests of the bridge indicate that the actual stress-strain state of the span structure is consistent with design values. The bridge can be taken under load NK-80. After the acceptance of the bridge structure by the working commission, traffic was opened for cars and pedestrians.

scholarly journals Numerical Modeling and Analysis of Concrete Slabs in Interaction with Subsoil

2020 ◽  
Vol 12 (23) ◽  
pp. 9868
Author(s):  
Radim Cajka ◽  
Zuzana Marcalikova ◽  
Vlastimil Bilek ◽  
Oldrich Sucharda
Keyword(s):  
Numerical Modeling ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Fiber Reinforced Concrete ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slab ◽  
Modeling And Analysis ◽  
Non Linear

This article focuses on the analysis and numerical modeling of a concrete slab interacting with subsoil. This is a complex task for which a number of factors enter into the calculation, including the scope or dimension of the model, the non-linear solution approach, the choice of input parameters, and so forth. The aim of this article is to present one possible approach, which is based on a non-linear analysis and a three-dimensional computational model. Five slabs were chosen for modeling and analysis. The experiments involved slabs of 2000 × 2000 mm and a thickness of 150 mm, which were tested using specialized equipment. The slabs included a reinforced concrete slab, a standard concrete slab, and three fiber-reinforced concrete slabs. The fiber-reinforced slabs had fiber volume fractions of 0.32%, 0.64%, and 0.96%, which corresponded to fiber dosages of 25, 50, and 75 kg/m3. A reinforced concrete slab was chosen for the calibration model and the initial parametric study. The numerical modeling itself was based on a detailed evaluation of experiments, tests, and recommendations. The finite element method was used to solve the three-dimensional numerical model, where the fracture-plastic material of the model was used for concrete and fiber-reinforced concrete. In this paper, the performed numerical analyses are compared and evaluated, and recommendations are made for solving this problem.

scholarly journals Ultimate Compressive Strains and Reserves of Bearing Capacity of Short RC Columns with Basalt Fiber

2021 ◽  
Vol 11 (16) ◽  
pp. 7634
Author(s):  
Aleksandr V. Shilov ◽  
Alexey N. Beskopylny ◽  
Besarion Meskhi ◽  
Dmitry Mailyan ◽  
Dmitry Shilov ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Basalt Fiber ◽  
Lightweight Aggregate ◽  
Short Fiber ◽  
Hydraulic Press ◽  
Steel Reinforcement ◽  
Fiber Reinforced Concrete ◽  
Material Consumption ◽  
Short Columns

Increasing the bearing capacity of reinforced concrete structures, reducing material consumption, and ensuring quality are critical in modern construction. The article presents an experimental study of the ultimate compressive strains of short fiber basalt reinforced concrete columns and provides recommendations for increasing the bearing capacity using steel reinforcement bars with greater strength. The columns were tested in an upright position using a hydraulic press. Strains were measured with dial indicators and a strain gauge station. It was shown that the addition of 10% coarse basalt fiber increased the ultimate compressibility of concrete on ordinary crushed stone by 19.8%, and expanded clay concrete by 26.1%, which led to the strain hardening of concrete under compression by 9.0% and 12%, respectively. Ultimate compressive strains in fiber-reinforced concrete short columns with combined reinforcement increased 1.42 times in columns on a lightweight aggregate and 1.19 times on heavy aggregate. An increase in the ultimate compressibility of concrete makes it possible to use steel reinforcement with greater strength in compressed elements as the concrete crushing during compression occurs primarily due to the reaching of critical values by tensile stresses in the transverse direction. This makes it possible to manufacture structures with a higher load-bearing capacity and less material consumption. A practical example of the application of the proposed approach is given.

Analysis on Punching Shear Behavior of the Raft Slab Reinforced with Steel Fibers

2008 ◽  
Vol 400-402 ◽  
pp. 335-340
Author(s):  
Xiao Wei Wang ◽  
Wen Ling Tian ◽  
Zhi Yuan Huang ◽  
Ming Jie Zhou ◽  
Xiao Yan Zhao
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Shear Behavior ◽  
Shear Capacity ◽  
Steel Fibers ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Mass Concrete ◽  
Reinforced Concrete Slab ◽  
The Common

The thickness of the raft slab is determined by punching shear. The raft slab is commonly thick, which causes concrete volume is large. Mass concrete can bring disadvantage to the foundation. In order to increase the bearing capacity and reduce the thickness, it is suggested that the raft slab to be reinforced by steel fibers. There are five groups of specimens in this paper. S1 is the common reinforced concrete slab. S2 and S3 are concrete slabs reinforced by steel fibers broadcasted layer by layer when casting specimen. S4 and S5 are concrete slabs reinforced by steel fibers mixed homogeneously when making concrete. The punching shear tests of these slabs were done. The test results indicate that the punching shear capacity of the slab reinforced with steel fibers is higher than that of concrete slab, the stiffness and crack resistance of the steel fibers reinforced concrete slab are better than those of the common concrete slab and the punching shear of the slabs with different construction methods of steel fibers is similar. It analyses the punching shear behavior of the slab reinforced with steel fibers and suggests the ultimate bearing formula. The calculative values are coincided with the measured values well.

Calculation of Reinforced Concrete Prismatic Shells by the Finite Element Method Using Variable Elasticity Parameters

2019 ◽  
Vol 945 ◽  
pp. 969-974
Author(s):  
V. Kruglov ◽  
V. Iurchenko
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Elements ◽  
Concrete Slab ◽  
Volume Ratio ◽  
High Strength ◽  
Finite Elements Method ◽  
Software Module ◽  
Reinforced Concrete Slab ◽  
Elastic Characteristics

The paper considers the modification of the generally accepted formulation of the finite elements method by applying in the calculation I.Mileykovski’s refined technical theory of shells that takes into account the deformations of the transverse shear along the thickness of the model. When applying this solution path, it is possible to calculate thick and thin shells (plates) with equal efficiency, taking into account the complex strained state of an anisotropic material. It illustrates the inclusion in the computational algorithm of variable parameters of the elasticity of concrete, allowing more accurate evaluation of the stress-strain state in the finite element under complex (combined) loads. The presence of reinforcement in the material is modeled by dividing the structure into layers and sequentially reduction the elastic characteristics of the material based on the volume ratio of the components. The advantage of the algorithm is the ease of its integration with the conventional finite elements method. All transformations in this case consist in the modification of expressions for determining the elastic characteristics of the construction, calculating the gradient and stiffness matrices, while the sequence of further calculations does not change. This enables to use the proposed algorithm, including as a plug-in software module, expanding the capabilities of existing computing programs. The article demonstrates the application of the method in modeling a reinforced concrete slab made with the use of multi-component high-strength concrete of a heavy class having a prismatic strength under uniaxial compression of more than 110 MPa.

Summary of Study on Composite Concrete Slabs

2013 ◽  
Vol 351-352 ◽  
pp. 695-698
Author(s):  
Lei Wang ◽  
Hong Ya Zhang
Keyword(s):  
Reinforced Concrete ◽  
Composite Structure ◽  
Concrete Slab ◽  
Engineering Application ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Recent Advances ◽  
The Future ◽  
At Home

Reinforced Concrete Slab is one of the important types of composite structure, About the concrete laminated slab of the research and the engineering application are summarized, Point out that the characteristics of Composite Concrete Slabs, the application and development of the laminated slab of recent advances at home and abroad, and look into the future of the Composite Concrete Slabs research.

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