scholarly journals STRUCTURAL FEATURES OF THE ASSEMBLIES OF THE JOINING OF TRAM RAILS TO ROAD COVERAGE

2021 ◽  
Vol 6 (166) ◽  
pp. 94-98
Author(s):  
O. Kalmykov ◽  
S. Hrybeniuk
Keyword(s):  
Reinforced Concrete ◽  
Asphalt Concrete ◽  
Concrete Slab ◽  
State Enterprise ◽  
Rolling Stock ◽  
Modern World ◽  
Electric Transport ◽  
Element Determination ◽  
Reinforced Concrete Slabs ◽  
Concrete Plates

In the modern world, the priority is the development of clean urban electric transport. The constructive solutions used in the construction of the tram wheel in the past years are outdated and do not meet modern requirements. One of these problems is the destruction of asphalt coating in the places of road coverage to tram rails, which worsens the operational characteristics of tram crossings. The reasons for this problem can be attributed to the following: Not enough asphalt concrete near the rails; low adhesion of asphalt and metal from which rails are made; dynamic loads and vibrations arising from trams and motor transport; bad base of tram train and others. One of the options for increasing reliability and durability is to use as a road covering of tram plates. This solution is used in Ukraine and the European Union. German company RailBeton developed solutions for railway crossings - BetoCross. This system is a modular construction of reinforced concrete slabs, which are pulled together by steel strips. With the help of a system of fastenings and bearings, the flooring is fastened to rails, which provides vertical and horizontal stability of their position and stabilization under the influence of loading. To reduce the dynamic influence, the plates are based on reinforced concrete sleepers through the intermediate layers of the elastostomer. The load from the automobile transport is transferred to the broken beam. In addition to the positive features, the BetoCross system, due to the large number of connections, ties and bearings, requires frequent maintenance and maintenance. The Ukrainian state enterprise "Starokostiantyniv plant ZBSH" developed a similar technology, reinforced concrete plates with the help of a screw fastening through rubber gasket fixed to a special bridge type wallpaper. At a step of wallpaper 0,6 m the plate is attached to each wallpaper from two sides, with the length of the plate itself is 2,7 m. that is, on one plate there are five points of fastening on each side. Loads from the automobile transport, similar to the German technology, are transferred to the rubble balast and the basis. These technological solutions have found their application on railway crossings, and need some improvement for use in urban electric transport. The article reviews the constructive decision on the organization of the mentioned site, which is proposed by RS ENGINEERING in Kharkov. In the proposed solution instead of the crushed balast used monolithic reinforced concrete slab with supporting elements. The arising loads from the rolling stock and transport are transferred through the supporting elements to the concrete slab, which redistributes them on the rubble basis. As a road cover are used reinforced concrete plates covering RS-Slab. The plates are divided into 3 types: Road, interroad and external, which in turn have several sizes. The plates are bound to the supporting elements by means of screws in four points. To reduce dynamic influence between the film and the reference element, a rubber elastomer is laid. Depending on the size of the plates have different number of cutting sites. Also because of the design features possible option when the slab simultaneously relies not on all the supporting sites, these options should be taken into account when calculating the scale and choosing a class of concrete. This solution allows to solve the problems of road surface destruction on the side of the rails, keeps more load from transport, compared to asphalt. At the same time, there are factors that need to be studied in detail when designing and before implementing the solution in mass production. These include: Investigation of the influence of violation of standard assembly plates on the stress-deformed state of the element; determination of thickness and acceptable physical characteristics of the gasket on the plate supports; detailed development of a node for fixing plates. The use of reinforced concrete plates as a road coating has a number of advantages before asphalt concrete: Resistance to destruction on the rails; installation regardless of weather and temperature conditions; resistance to loads from trucks. At the same time, this decision has certain peculiarities that require detailed study, which is a branch of further research.

scholarly journals Effect of the Geometrical Constraints to the Wenner Four-Point Electrical Resistivity Test of Reinforced Concrete Slabs

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4622
Author(s):  
Kevin Paolo V. Robles ◽  
Jurng-Jae Yee ◽  
Seong-Hoon Kee
Keyword(s):  
Experimental Investigation ◽  
Electrical Resistivity ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Plain Concrete ◽  
Electrode Spacing ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Spacing Ratio ◽  
Geometrical Constraints

The main objectives of this study are to evaluate the effect of geometrical constraints of plain concrete and reinforced concrete slabs on the Wenner four-point concrete electrical resistivity (ER) test through numerical and experimental investigation and to propose measurement recommendations for laboratory and field specimens. First, a series of numerical simulations was performed using a 3D finite element model to investigate the effects of geometrical constraints (the dimension of concrete slabs, the electrode spacing and configuration, and the distance of the electrode to the edges of concrete slabs) on ER measurements of concrete. Next, a reinforced concrete slab specimen (1500 mm (width) by 1500 mm (length) by 300 mm (thickness)) was used for experimental investigation and validation of the numerical simulation results. Based on the analytical and experimental results, it is concluded that measured ER values of regularly shaped concrete elements are strongly dependent on the distance-to-spacing ratio of ER probes (i.e., distance of the electrode in ER probes to the edges and/or the bottom of the concrete slabs normalized by the electrode spacing). For the plain concrete, it is inferred that the thickness of the concrete member should be at least three times the electrode spacing. In addition, the distance should be more than twice the electrode spacing to make the edge effect almost negligible. It is observed that the findings from the plain concrete are also valid for the reinforced concrete. However, for the reinforced concrete, the ER values are also affected by the presence of reinforcing steel and saturation of concrete, which could cause disruptions in ER measurements

Numerical Analysis of Anti-Impact Performances of the Reinforced Concrete Slab

2012 ◽  
Vol 249-250 ◽  
pp. 1063-1068
Author(s):  
Qian Ma ◽  
Dan Wu ◽  
Xu Dong Shi ◽  
Xiu Gen Jiang
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Impact Resistance ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs ◽  
Steel Bar ◽  
Parameterized Modeling ◽  
Element Theory ◽  
Bar Diameter

The influence of the structure parameters on the anti-impact performances of the reinforced concrete slab is studied in the article. The reinforced concrete model is established by using ANSYS 13.0/LS-DYNA and nonlinear finite element theory and the parameterized modeling is achieved. The results show that the increase of the thickness of the slab and the steel bar diameter result in the enhancement of impact resistant capability of the slab; a appropriate quantity of reinforcement is significant; Increasing the concrete strength has a distinct impact on the slab’s impact resistance when using relatively low strength concrete. However the influence becomes weak after the concrete strength comes to C60 and higher. The fruits are useful to the designing of reinforced concrete slabs.

scholarly journals Reinforced Concrete Slab Optimization with Simulated Annealing

2019 ◽  
Vol 9 (15) ◽  
pp. 3161
Author(s):  
Flavio Stochino ◽  
Fernando Lopez Gayarre
Keyword(s):  
Simulated Annealing ◽  
Reinforced Concrete ◽  
Structural Optimization ◽  
Virtual Work ◽  
Concrete Slab ◽  
Limit State ◽  
Slab Thickness ◽  
Ultimate Limit State ◽  
Space Partitioning ◽  
Reinforced Concrete Slabs

Flat slabs have several advantages such as a reduced and simpler formwork, versatility, and easier space partitioning, thus making them an economical and efficient structural system. When producing structural components in series, every detail can lead to significant cost differences. In these cases, structural optimization is of paramount relevance. This paper reports on the structural optimization of reinforced concrete slabs, presenting the case of a rectangular slab with two clamped adjacent edges and two simply supported edges. Using the yield lines method and the principle of virtual work, a cost function can be formulated and optimized using simulated annealing (SA). Thus, the optimal distribution of reinforcing bars and slab thickness can be found considering the flexural ultimate limit state and market materials costs. The optimum result was defined by the orthotropic coefficient k = 8, anisotropic coefficient g = 1.4, and slab thickness H = 11.8 cm. A sensitivity analysis of the solution was developed considering different material costs.

Critical Review of Design Procedures for Reinforced Concrete Slabs as per IRC 112-2011

2019 ◽  
Vol 969 ◽  
pp. 349-354 ◽  
Author(s):  
J. Chithra ◽  
Praveen Nagarajan ◽  
A.S. Sajith ◽  
R.A. Roshan
Keyword(s):  
Reinforced Concrete ◽  
Critical Review ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Finite Element Software ◽  
Reinforced Concrete Slabs ◽  
Distributed Load ◽  
Uniformly Distributed Load ◽  
Sandwich Model

Nowadays finite element software is used for the design and analysis of reinforced concrete slabs. This paper intends to have a critical review based on a comparison study between the three design methods and to estimate the amount of reinforcement to be provided in each case. The three methods discussed are; the three-layer sandwich model (IRC 112-2011), Wood Armer method (EN1992-1-1:2004) and the conventional design method as per IS 456-2000. In the recently revised code for bridges IRC 112-2011, there is a recommendation to adopt three-layer sandwich model for the design of reinforced concrete slab. In this paper, a critical review of this method is done, and it is used for slabs subjected to uniformly distributed load. This method is illustrated by considering the design of rectangular slab subjected to uniformly distributed load. The results of this method are compared with the results obtained using Wood Armer method and using the moment coefficients suggested in IS 456-2000.

THE EFFECT OF IMPACT LOADS ON PRESTRESSED CONCRETE SLABS

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Youmn Al Rawi ◽  
Yehya Temsah ◽  
Hassan Ghanem ◽  
Ali Jahami ◽  
Mohamad Elani
Keyword(s):  
Reinforced Concrete ◽  
Prestressed Concrete ◽  
Impact Loading ◽  
Concrete Slab ◽  
Concrete Slabs ◽  
Shear Mode ◽  
Reinforced Concrete Slab ◽  
Finite Element Program ◽  
Reinforced Concrete Slabs ◽  
The Impact

Many research studies have been conducted on the effect of impact loading on structures, and design procedures were proposed for reinforced concrete (RC) slabs; however the availability of these studies and procedures are limited for prestressed slabs. The proposed research will examine, using numerical analysis, the impact of rock fall on prestressed concrete slabs with equivalent moment capacity reinforced concrete slabs. It is expected that prestressed concrete slabs will have different behavior to resist impact loading compared with traditional reinforced concrete slabs. The thickness of the prestressed concrete slab will be 25cm whereas that of the reinforced concrete slab will be 30cm. The impact loading consists of 500Kg drop weight. The drop height will be 10m, 15m and 20m.The structural analysis is performed using a Finite Element program "ABAQUS". A comparison will be done between both slab types in terms of failure mode, damage, and deflection. It has been found that both slabs failed in punching. However, the RC slab performed better than the prestressed concrete slab with respect to the value of the deflection at mid-span, while both showed punching shear mode of failure.

BEHAVIOR OF REINFORCED CONCRETE SLABS UNDER ACCIDENTAL IMPACTS

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Shamsoon Fareed
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Concrete Slab ◽  
High Mass ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs ◽  
Numerical Predictions ◽  
Operational Life ◽  
The Impact

Loads resulting from activities such as rock fall, heavy drop weights (for e.g. equipment's, heavy machines during installation), missile and aircraft interaction with slabs may results in loading intensity which have higher magnitude as compared to static loading. Based on the velocity of the impacting object at the time of contact, these activities may result in impact loading. Therefore, slabs designed should provide resistance to these accidental loading during their entire operational life. In this study, a dynamic non-linear finite element analyses were conducted to investigate the behavior of the reinforced concrete slabs subjected to high-mass low-velocity impacts. For this purpose, initially an already published impact test results were used to validate the numerical predictions. Following validation, a study was conducted to investigate the influence of the impact velocity on the behavior of the reinforced concrete slab. Based on the numerical investigation, it was found that the velocity of the impacting object has a significant influence on the behavior exhibited by slab under impact loading. Furthermore, it was also found that the behavior of slab under impact is both local and global. Local behavior is associated with the damage caused at the contact area of the slab and the impactor, whereas global behavior refers to the overall deformation of the slab when stress waves move away from the impact zone and travel towards the supports.

scholarly journals Finite Difference Energy Method for nonlinear numerical analysis of reinforced concrete slab using simplified isotropic damage model

2014 ◽  
Vol 7 (6) ◽  
pp. 940-964
Author(s):  
M. V. A. Lima ◽  
J. M. F. Lima ◽  
P. R. L. Lima
Keyword(s):  
Reinforced Concrete ◽  
Finite Difference ◽  
Energy Method ◽  
Virtual Work ◽  
Concrete Slab ◽  
Damage Model ◽  
Flexural Behavior ◽  
Structural Element ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs

This work presents a model to predict the flexural behavior of reinforced concrete slabs, combining the Mazars damage model for simulation of the loss of stiffness of the concrete during the cracking process and the Classical Theory of Laminates, to govern the bending of the structural element. A variational formulation based on the principle of virtual work was developed for the model, and then treated numerically according to the Finite Difference Energy Method, with the end result a program developed in Fortran. To validate the model thus proposed have been simulated with the program, some cases of slabs in flexure in the literature. The evaluation of the results obtained in this study demonstrated the capability of the model, in view of the good predictability of the behavior of slabs in flexure, sweeping the path of equilibrium to the rupture of the structural element. Besides the satisfactory prediction of the behavior observed as positive aspects of the model to its relative simplicity and reduced number of experimental parameters necessary for modeling.

scholarly journals Performance of Self-Compacted Reactive Powder Concrete Slab Under Harmonic Dynamic Loading

2019 ◽  
Vol 26 (1) ◽  
pp. 89-99
Author(s):  
Mohammad Makki Abbass Bilal ◽  
Mohamad Adnan Mohamad
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Loading ◽  
Static Loading ◽  
Concrete Slab ◽  
Reactive Powder Concrete ◽  
Concrete Slabs ◽  
Dynamic Resistance ◽  
Structural Element ◽  
Reinforced Concrete Slabs ◽  
Reactive Powder

Many types of loading the structure must sustain in addition to dead and live loads according to the function of structural element type that must be taken in analysis.  Dynamic resistance to loading of reinforced concrete slabs using self-compact reactive powder concrete, with different boundary conditions at the sides in addition of static loading was studied. The reinforced concrete slabs were designed under static load according to ACI-318R-2014 and then the adequacy was checked under harmonic dynamic loading. The static loading consists of dead load and residential live load considering according to ASCE-07-2010. Modeling analysis was performed to determine the eigenvalues and eigenvectors values and then frequency response analyses of the slab by finite elements method that adopted for analysis. The results indicated that in case of self-compacted reactive powder concrete rather than normal concrete gave deflection less and also there was a different result of deflection according the type of slab boundary condition supports.

scholarly journals Investigation on Structural Behavior of Bamboo Reinforced Concrete Slabs under Concentrated Load

2021 ◽  
Vol 50 (1) ◽  
pp. 227-238
Author(s):  
Yanuar Haryanto ◽  
Nanang Gunawan Wariyatno ◽  
Hsuan-Teh Hu ◽  
Ay Lie Han ◽  
Banu Ardi Hidayat
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Absorption Capacity ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Slabs ◽  
Cracking Pattern

Reinforced concrete is perhaps the most widely used building material in the world. However, the materials used for reinforcement of concrete i.e. steel is quite expensive and scarcely available in the developing world. As a result, bamboo is considered to be a cheaper replacement with high tensile strength. This research investigated the structural behaviour of bamboo-reinforced concrete slabs used for footplate foundation subjected to concentrated load. For this purpose, four different reinforced concrete slab panels were developed and analyzed. The influence of replacing steel with bamboo for the reinforcement of concrete slabs on their structural behaviour was assessed by determining the load-deflection characteristics, the ultimate load, the stiffness, the ductility, the cracking pattern, and the energy absorption capacity. The results showed that in comparison to steel reinforced concrete slabs, the strength of 82% can be acquired by the bamboo reinforced slabs. Furthermore, ductility demonstrated by the two types of specimens was almost equivalent i.e. up to 93%. Those indicated that the structural behaviour demonstrated by bamboo reinforced slabs is quite comparable to that of steel reinforced concrete slabs. Therefore, bamboo can prove to be a promising substitute for steel in concrete reinforcement. Future studies may further examine this opportunity.

scholarly journals Analysis of Fiber-Reinforced Concrete Slabs under Centric and Eccentric Load

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7152
Author(s):  
Zuzana Marcalikova ◽  
Vlastimil Bilek ◽  
Oldrich Sucharda ◽  
Radim Cajka
Keyword(s):  
Tensile Strength ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Fiber Reinforced Concrete ◽  
Experimental Program ◽  
Concrete Slabs ◽  
Detailed Knowledge ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
3D Deformation

Research on the interaction between slabs and subsoil involves the field of materials engineering, concrete structures, and geotechnics. In the vast majority of cases, research focuses on only one of these areas, whereas for advanced study and computer simulations, detailed knowledge of the whole task is required. Among the new knowledge and information upon which this article focuses is the evaluation of subsoil stress using specialized pressure cells, along with detailed measurements of the deformation of a fiber-reinforced concrete slab. From a design point of view, this research is focused on the issue of the center of the cross section and the influence of eccentricity. Knowledge in this area is not yet comprehensively available for fiber-reinforced concrete slabs, where 2D deformation sections of the slab and 3D deformation surfaces of the slab are used in experiments. The experimental program includes a centrically and eccentrically loaded slab. These are structural elements that were tested on a specialized device. Both slabs had the same concrete recipe, with a dispersed reinforcement content of 25 kg/m3. The dimensions of the slab were 2000 × 2000 × 150 mm. Laboratory tests assessed compressive strength, the modulus of elasticity, splitting tensile strength, and bending tensile strength. Based on approximate data from the 3D deformation surfaces, an evaluation of the load-displacement diagrams for the center of the slab and for the center of eccentricity was performed. In conclusion, an overall evaluation and discussion of the results relies on experiments and the mechanical properties of fiber-reinforced concrete.

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