scholarly journals Modelling of motorway bridge spans under modernization with consideration of rheological properties of the materials

2018 ◽  
Vol 234 ◽  
pp. 04004 ◽  
Author(s):  
Alexey Lobiak ◽  
Andrii Plugin ◽  
Larisa Kravtsiv ◽  
Oksana Kovalova
Keyword(s):  
Rheological Properties ◽  
Computer Modelling ◽  
Concrete Slab ◽  
Kinetic Curve ◽  
Modelling Technique ◽  
Reinforced Concrete Slab ◽  
Program Complex ◽  
Building Information ◽  
Lev Landau ◽  
The Impact

The paper presents a computer modelling technique for modernization of bridgework operations by building-up a mounted reinforced concrete slab. It implements the technique of the evolutionary transformation of a model in one calculation cycle with redistribution of forces between the elements of the built-up section, and consideration of the impact of elastoplastic and rheological properties of the materials. Consideration of the concrete creep implies the application of the generalized kinetic curve of prolonged deformation and phenomenological deformation development equations based on the colloid-chemical concept of the prolonged concrete deformation mechanism. The creep control was implemented through new structural coefficients which determined the structure of matrix interlayers between the sand grains, and mortar between the crushed stone grains. The technique proposed was realized in the program complex “LIRA-SAPR” based on the building information modelling (BIM) and the finite element method (FEM). The multistage modelling technique was shown by an example of calculation of a motorway bridge slab span within the transport structures under modernization along the Lev Landau Avenue in Kharkiv (Ukraine).

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.

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.

Theoretical Method of Calculation to Determination the Change of Axial Force in a Reinforcing Bar during the Destruction of the Support Zone of the Central Column in the RC Structures

2016 ◽  
Vol 821 ◽  
pp. 555-562
Author(s):  
Barbara Wieczorek
Keyword(s):  
Structural Integrity ◽  
Concrete Slab ◽  
Tensile Force ◽  
Experimental Investigations ◽  
Reinforced Concrete Slab ◽  
Linear Change ◽  
Rc Structures ◽  
Method Of Calculation ◽  
Support Zone ◽  
The Impact

The behaviour of reinforced concrete slab-column structures under the impact of accidental loading is very significant due to safety reasons. The failure of the support zone by punching and lack of proper structural integrity reinforcement can lead to a progressive collapse. However, the instructions on how to prevent such situations are not very detailed. According to the guidelines of standard EC2, the structural integrity reinforcement should be continuous throughout the length and consist of at least two bars above the column in every perpendicular direction. EC2 does not state the amount of necessary reinforcement. The article presents a theoretical model of calculation that permits a more detailed analysis of internal forces in reinforcing bars located directly above the column. Adopting a solution in the form of exact equations makes it possible to take into account the influence of a non-linear change of the bar rigidity and considerable deflections. The calculation model was verified on the basis of the results of experimental investigations. It enables to estimate the tensile force of the bar at which it is ruptured during the destruction of the support zone.

scholarly journals Long-term study of the impact of temperature changes, material aging and service load on the strains of a reinforced concrete structure

2018 ◽  
Vol 66 ◽  
pp. 02006
Author(s):  
Adam Kanciruk
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Reinforced Concrete Structure ◽  
Reinforced Concrete Slab ◽  
Temperature Changes ◽  
Long Term Study ◽  
Monitoring Process ◽  
Service Load ◽  
The Impact

The article discusses five year long measurements of strains of a concrete floor of a hangar. That hangar, originally meant for servicing light military aircraft, was rebuilt with a view to making it fit for servicing larger and heavier passenger planes. As part of that redevelopment, a new floor - reinforced concrete slab, capable of withstanding the weight of the planes - was constructed. In the areas of the floor where the greatest loads occur, ie. in the areas of the concrete slab on which the wheels of the three undercarriage legs rest, three strain rosettes were installed so that the slab strains could be measured. The rosettes were connected to two meters - dataloggers. The latter were programmed in such a way as to register the measured strains and additionally temperatures many times during every 24 hours. The monitoring process, conducted in such an automatic way, demonstrated the occurrence of strains resulting from service load, aging of the reinforced concrete, as well as changes in its temperature.

scholarly journals Finite Element Analysis of the Stability of a Sinusoidal Web in Steel and Composite Steel-Concrete Girders

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1041 ◽  
Author(s):  
Krzysztof Śledziewski ◽  
Marcin Górecki
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Initial Stresses ◽  
Shear Stresses ◽  
Reinforced Concrete Slab ◽  
The Stability ◽  
The Impact ◽  
The Web ◽  
Composite Steel

This paper presents the results of numerical investigations into the behavior of a sinusoidal web loaded in shear due to buckling in the period from the onset of buckling until failure, as well as the impact of a reinforced concrete slab on the stability of the web. The analysis concerned steel girders and composite girders with the top flange bonded to a reinforced concrete slab. Nonlinear analyses were performed using the finite element method. The results of the investigations support the conclusion that the appearance and propagation of shear stresses in the sinusoidal web of the composite steel–concrete beam are the same as those in an identical non-composite steel beam, but the bracing of the top flanges improves the shear strength and, at the same time, affects the location of initial stresses. In addition, it was found that, despite the three types of buckling, the predominant failure of the sinusoidal webs, regardless of the presence of the concrete slab, is global buckling. It occurs diagonally through several folds at the same time, including deformation of the web over its entire height.

scholarly journals Impact Testing on Reinforced Concrete Slab with Bfrp Bars as Reinforcement

2019 ◽  
Vol 8 (6) ◽  
pp. 286-288
Keyword(s):  
Reinforced Concrete ◽  
Impact Strength ◽  
Bending Strength ◽  
Concrete Slab ◽  
Impact Testing ◽  
Basalt Fibre ◽  
Reinforced Concrete Slab ◽  
Length Width ◽  
Considerable Impact ◽  
The Impact

Basalt Fibre Reinforced Polymer (BFRP) bar is an alternative to steel and glass fibre for reinforced concrete. Their unique characteristics makes them favourable compared to the other alternative materials. According to previous studies the BFRPbars are lighter and stronger than steel and has higher bending strength. But the research regarding the impact strength of BFRP bars are very limited. But the impact strength of materials is very important for many critical designs due. Thus, prompting the study of impact strength of BFRP bars. Basic tests were done to determine the strength of the materials to be used. Slabs of 550mm ×550mm ×50mm are made with varying centre to centre distance between bars in both cases of steel and basalt bars. The slabs are subjected to impact loading through the drop weight impact and the values such as crack length, width and depth are observed, and the result is observed in the form of ultimate crack resistance. Even though slabs with maximum centre to centre distance between bars failed very easily in both cases, the slabs with minimum centre to centre distance between bars gave considerable impact strength

Exploring the Benefits of Early Contractor Involvement (ECI) and the Mechanism for Automated 5D BIM Quantification Process in Offsite Modular Construction

2016 ◽  
Author(s):  
Tochukwu Moses ◽  
David Heesom ◽  
David Oloke ◽  
Martin Crouch
Keyword(s):  
Effective Means ◽  
Cost Effective ◽  
Modular Construction ◽  
Automated Quantification ◽  
Building Information ◽  
Project Risks ◽  
Value Add ◽  
The Uk ◽  
The Impact ◽  
Level 2

The UK Construction Industry through its Government Construction Strategy has recently been mandated to implement Level 2 Building Information Modelling (BIM) on public sector projects. This move, along with other initiatives is key to driving a requirement for 25% cost reduction (establishing the most cost-effective means) on. Other key deliverables within the strategy include reduction in overall project time, early contractor involvement, improved sustainability and enhanced product quality. Collaboration and integrated project delivery is central to the level 2 implementation strategy yet the key protocols or standards relative to cost within BIM processes is not well defined. As offsite construction becomes more prolific within the UK construction sector, this construction approach coupled with BIM, particularly 5D automated quantification process, and early contractor involvement provides significant opportunities for the sector to meet government targets. Early contractor involvement is supported by both the industry and the successive Governments as a credible means to avoid and manage project risks, encourage innovation and value add, making cost and project time predictable, and improving outcomes. The contractor is seen as an expert in construction and could be counter intuitive to exclude such valuable expertise from the pre-construction phase especially with the BIM intent of äóÖbuild it twiceäó», once virtually and once physically. In particular when offsite construction is used, the contractoräó»s construction expertise should be leveraged for the virtual build in BIM-designed projects to ensure a fully streamlined process. Building in a layer of automated costing through 5D BIM will bring about a more robust method of quantification and can help to deliver the 25% reduction in overall cost of a project. Using a literature review and a case study, this paper will look into the benefits of Early Contractor Involvement (ECI) and the impact of 5D BIM on the offsite construction process.

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