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.

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.

Microcomputer analysis of reinforced concrete slab systems

1993 ◽  
Vol 20 (4) ◽  
pp. 587-601 ◽  
Author(s):  
Pierre Léger ◽  
Patrick Paultre
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Structural Design ◽  
Concrete Slab ◽  
Three Dimensional ◽  
Structural Behaviour ◽  
Reinforced Concrete Slab ◽  
Element Analysis ◽  
Equivalent Frame ◽  
Frame Method

Microcomputer finite element analysis of reinforced concrete slab systems can now be routinely performed to produce realistic numerical simulation of three-dimensional structural behaviour. However, an efficient use of this approach requires an automated integration of design and analysis procedures. Guidelines for proper finite element modelling of slab systems are first presented along with simple post-processing algorithms to perform automatically the design or verifications from the analytical results. Numerical applications on simple slab systems subjected to uniform and concentrated loads are then used to illustrate the relative performance between finite element analyses and the equivalent frame method. Key words: microcomputer, reinforced concrete slab, finite element method, structural design.

Coupled Discrete Element/Finite Element Method for the Analysis of Large Reinforced Concrete Structures Submitted to an Impact

2011 ◽  
Vol 82 ◽  
pp. 284-289
Author(s):  
Laurent Daudeville ◽  
Jessica Haelewyn ◽  
Philippe Marin ◽  
Serguei Potapov
Keyword(s):  
Reinforced Concrete ◽  
Finite Elements ◽  
Heterogeneous Media ◽  
Concrete Slab ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Elements ◽  
Reinforced Concrete Slab ◽  
The Impact ◽  
Element Method

The efficiency of the discrete element method for studying the fracture of heterogeneous media has been demonstrated, but it is limited by the size of the computational model. A coupling between the discrete elements (DEM) and the finite elements (FEM) methods is proposed to handle the simulation of impacts on large structures. The structure is split into two subdomains in each of which the method is adapted to the behavior of the structure under impact. The DEM takes naturally into account the discontinuities and is used to model the media in the impact zone. The remaining structure is modeled by the FEM. We propose an adaptation of the coupling procedure to connect Discrete Element model to shell-type Finite Elements. Finally, the efficiency of this approach is shown on the simulation of a reinforced concrete slab impacted by a tubular impactor.

Flexural Strength of Reinforced Concrete Two way Slabs Strengthened and Repaired by High Strength Ferrocement at Tension Zone

2017 ◽  
Vol 5 (1) ◽  
pp. 104-119
Author(s):  
Mazen D. Abdullah ◽  
Mustafa Sheriff ◽  
Aqeel Hateem
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Slab ◽  
High Strength ◽  
Wire Mesh ◽  
Flexural Behavior ◽  
Tension Zone ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Simply Supported

     This paper presents a study of the flexural behavior of strengthened and repaired reinforced concrete two slabs by ferrocement layers.  This study included testing 11 simply supported two way slabs, which include 1 control slabs, 8 strengthened slabs and 2 repaired slabs. In the strengthened slabs the effect of the thickness of ferrocement layers, the compressive strength for mortar and number of wire mesh layers of ferrocement on the ultimate load, mid span deflection at ultimate load and intensity of cracks was investigate. In the repaired part the slabs were loaded to (74 %) of measured ultimate load of control slab. The effect of connection method between repaired slabs and ferrocement jacket on the ultimate load, mid span deflection at ultimate load and intensity of cracks was examined. All reinforced concrete slab specimens were designed of the same dimensions and reinforce identically to fail in flexure. All slabs have been tested in simply supported conditions subjected to central concentrated load. The experimental results show that the ultimate loads are increased by about (4.6-19.2%) for the slabs strengthened with ferrocement with respect to the unstrengthened reinforced concrete slab (control slab).

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 The search for sustainable parameters for steel-reinforced concrete section of a bridge superstructure

2018 ◽  
Vol 230 ◽  
pp. 02015
Author(s):  
Yuriy Krul ◽  
Roman Kaplin
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
High Strength ◽  
Theoretical Models ◽  
Iteration Algorithm ◽  
Geometrical Parameters ◽  
Slab Thickness ◽  
Reinforced Concrete Slab ◽  
Steel Reinforced Concrete ◽  
Bridge Superstructure

The article contains the description of an efficient lightweight steel-reinforced concrete bridge superstructure, which includes metal blocks with a box-like section and reinforced concrete efficient roadway slab. Metal blocks are made of sheet perforated elements manufactured according to the no-waste technology. The blocks are interconnected as a single space bridge superstructure frame by means of high strength bolts. The reinforced concrete slab of the roadway is an efficient hollow slab. It includes upper and lower housing, inner ribs placed with a particular pitch, and all its remained part is filled with polystyrene foam extractable fillers along its height. At this, a rib height is equal to the full slab height. The metal and reinforced concrete parts are linked by means of a special system of shearing connections. The article describes an iteration algorithm of the construction enhancement, in course of which the geometrical parameters, such as bridge superstructure section full height, reinforced concrete slab thickness and a construction metal part height were defined. Theoretical models being the ground for the strain-stress state (SSS) of the sections studied analysis were developed.

Sign in / Sign up

Export Citation Format

Share Document