scholarly journals Bridge assessment: A case study of Ajaokuta-Itobe Bridge, Kogi State

2021 ◽  
Vol 2 (2) ◽  
pp. 066-078
Author(s):  
Ibrahim AInuwa ◽  
Abubakar Musa Yola ◽  
Hassan Abba Musa ◽  
Victor Mlanga ◽  
Umar Shuaibu
Keyword(s):  
Concrete Strength ◽  
Strength Test ◽  
Steel Beams ◽  
Expansion Joint ◽  
Protection Measures ◽  
Expansion Joints ◽  
The Public ◽  
Steel Members ◽  
River Bed ◽  
Bridge Foundation

This report summarizes the assessment carried out as a result of the public uproar on the degree of safety of the Ajaokuta/Itobe Bridge in Kogi state. The public outcry was as a result of a severe damaged expansion joints of the bridge. Visual inspection and concrete strength test were carried out to ascertain the safety condition of Itobe Bridge. Seven out of the total number of eight expansion joint covers were damaged and out of place while all the elastomeric bearings were in good working condition. The scouring of the river bed was not visually pronounced except little at the abutment side of the Abuja-Ayingba approach which is attributed to change of water course. Farming activities within the vicinity of the bridge embankment has no effects on the bridge foundation. The compressive strength test result of some bridge elements selected shows that the values are within the satisfactory range. The assessment recommended the lengthening and desilting of the drainage pipes to prevent further corrosion of the concrete and steel members. The use of sand blasting and repainting of the steel beams was also recommended to protect them from further corrosion. Maintenance of cracks on the reinforced concrete abutment and piers should be carried out. The use of sheet piles filled with compacted sand or gabions around the exposed piles caps to protect the foundation was recommended. Shoreline protection measures should be used in protecting the bridge eroded embankment. Seven out of eight expansion joint devices were damaged therefore exposing the elements of the structure that are otherwise protected by the joint devices. The openings about 47cm-53cm becomes a conduit by which moisture, abrasives, chemicals, and other debris are deposited on the superstructure and substructure below the opening, thereby causing extensive damage. The expansion joints devices should be fixed with proper elastomeric strip seal to protect the bridge from further deterioration.

Experimental Study on Mix Ratio Design and Road Performance of Medium and Small Deformation Seamless Expansion Joints of Bridges

2021 ◽  
pp. 036119812098474
Author(s):  
Pengzhen Lu ◽  
Chenhao Zhou ◽  
Simin Huang ◽  
Yang Shen ◽  
Yilong Pan
Keyword(s):  
Traffic Safety ◽  
Performance Test ◽  
Asphalt Mixture ◽  
Small Deformation ◽  
Expansion Joint ◽  
Expansion Joints ◽  
Mixture Ratio ◽  
The Road ◽  
Marshall Test ◽  
Road Performance

Expansion joints are a weak and fragile part of bridge superstructure. The damage or failure of the expansion joint will lead to the decline of bridge durability and endanger the bridge structure and traffic safety. To improve the service life and performance of bridge expansion joints, the ideal method is to use seamless expansion joints. In this study, starting from the commonly used asphalt mixture gradation of seamless expansion joint, and taking into account the actual situation of bridge expansion joint structure and environment in China, the gradation and asphalt-aggregate ratio are preliminarily designed. Through a Marshall test, the corresponding asphalt mixture is evaluated and analyzed according to the stability, flow value, and void ratio, and the optimal gradation and asphalt-aggregate ratio are determined. Finally, the asphalt mixture is prepared with the mixture ratio design, and the test results of an immersion Marshall test, fatigue performance test, and full-scale test verify that the asphalt mixture meets the road performance requirements of seamless expansion joints. On the basis of the experimental data, the performance of large sample asphalt mixture is continuously tested, compared, and optimized. The results show that the asphalt mixture ratio designed is true and reliable, which can provide reference for the optimal design of seamless expansion joint filler.

scholarly journals Experimental Study on Doweled Expansion Joints on Behavior for Plain Concrete Pavement System

2018 ◽  
Vol 14 (3) ◽  
pp. 68-80
Author(s):  
Zainab Ahmed Al-kaissi ◽  
Mohammed Hashim Mohammed ◽  
Nabaa Sattar Kareem
Keyword(s):  
Failure Load ◽  
Concrete Slab ◽  
Concrete Strength ◽  
Plain Concrete ◽  
Concrete Pavement ◽  
Type I ◽  
Expansion Joints ◽  
Subgrade Soil ◽  
Dowel Bar ◽  
Bar Diameter

This paper deals with load-deflection behavior the jointed plain concrete pavement system using steel dowel bars as a mechanism to transmit load across the expansion joints. Experimentally, four models of the jointed plain concrete pavement system were made, each model consists of two slabs of plain concrete that connected together across expansion by two dowel bars and the concrete slab were supported by the subgrade soil. Two variables were dealt with, the first is diameter of dowel bar (12, 16 and 20 mm) and the second is type of the subgrade soil, two types of soil were used which classified according to the (AASHTO): Type I (A-6) and type II (A-7-6). Experimental results showed that increasing dowel bar diameter from 12 mm to 20 mm has a little effect on load-deflection behavior of the tested specimens with only 5% increase in failure load. This may be attributed to that the failure (caused by flexural crack) depends mainly on concrete strength. Results also showed that decreasing CBR value of subgrade soil from 7% to 5% decreases failure load by about 33%.

The Implications of Religious Liberty

2017 ◽  
pp. 143-162
Keyword(s):  
Religious Freedom ◽  
Religious Liberty ◽  
The Political ◽  
Marriage Equality ◽  
Same Sex ◽  
Protection Measures ◽  
Same Sex Marriage ◽  
Public Discussion ◽  
The Public ◽  
Faith Based

The political terrain surrounding the legalization of same-sex marriage and the need to accommodate individual's faith based objections have been part of the public discussion since the passage of initial marriage equality statutes. These exemptions played an important part in the bill's passage and have gone largely unquestioned from proponents of marriage equality. This chapter discusses the heightened lawmaking efforts by opponents insisting on broad protection measures for religious claims based on opposition directed towards homosexuality. This Chapter discusses the resulting tension between religious freedom and marriage equality.

scholarly journals Influence of the Acoustic Cover of the Modular Expansion Joint on the Acoustic Climate in the Bridge Structure Surroundings

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2842
Author(s):  
Janusz Bohatkiewicz ◽  
Michał Jukowski ◽  
Maciej Hałucha ◽  
Marcin Dębiński
Keyword(s):  
Sound Level ◽  
Structural Elements ◽  
Expansion Joint ◽  
Expansion Joints ◽  
The Road ◽  
Sound Levels ◽  
Road Surfaces ◽  
Before And After ◽  
Bridge Structures

The noise generated at the interface between the wheels of vehicles and the road surface is well recognized in the literature worldwide. Many publications describe the phenomenon of reducing this kind of impact by silent road surfaces. A specific type of this noise is the sound generated by vehicles passing over the expansion joints of bridge structures. Due to the impulsive nature of this sound, it is very onerous for people living in the close vicinity of bridge structures. The passage of vehicles over expansion joints causes the formation of vibrations that are transmitted to the structural elements of bridge structures, which may cause the formation of the material sounds (especially arduous in the case of bridges with steel elements). An attempt to reduce this impact was made by making a prototype acoustic cover of the expansion joint on the selected bridge. The paper presents the results of research on the “in situ” acoustic effectiveness of this cover. Additionally, the noise was modelled in the object surroundings before and after the cover’s application. The acoustic efficiency of the cover in the whole measured frequency range was 5.3 dBA. In the narrower frequency bands (1/3 octave bands), larger sound level reductions were observed. The maximum sound levels measured under the tested dilatation were less than 10.0 dBA lower than the maximum sound levels measured under the reference dilatation.

Automatic Assembly and Key Technologies of Expansion Joints

2011 ◽  
Vol 109 ◽  
pp. 420-423
Author(s):  
Yan Kai Fang
Keyword(s):  
Parametric Modeling ◽  
Modeling Method ◽  
Cycle Life ◽  
Secondary Development ◽  
Automatic Assembly ◽  
Expansion Joint ◽  
Expansion Joints ◽  
Key Technologies ◽  
Graphics Software

Expansion joints are non-standard devices whose shape and parameters could vary with temperature, pressure, displacement and cycle life, so it's drawing work is very burdensome. Expansion joint industry is badly in need a set of accurate, reliable and stong practical professional graphics software. Therefore this paper carried out targeted secondary development of the software on the basis of digestion and absorption of SolidWorks2010 so as to meet the urgent needs of expansion joints industry. The structure of most parts of bellows expansion joints is not complex, and their geometry are relatively simple and fixed, so it is very suitable for parametric modeling method.

Satisfying Piping Stress and Flexibility Requirements With the Implementation of Expansion Joints: Techno-Economical Optimization

2012 ◽  
Author(s):  
Misa Jocic
Keyword(s):  
Traditional Method ◽  
Technical Specification ◽  
Manufacturing Companies ◽  
Expansion Joint ◽  
Expansion Joints ◽  
The Past ◽  
Pipe Routing ◽  
Piping Systems ◽  
Economical Optimization ◽  
Design And Construction

There have been various attempts to deal with the optimization of solutions which involve expansion joints in piping systems where sufficient flexibility can’t be found using suitable pipe routing. The difficulty of piping designs which involve expansion joints is that they rely upon two engineering expertises: Pipe Flexibility and Stress Analysis on one side and Expansion Joint Design and Construction on the other. Arguably distinctively different, they have been looked upon as totally detached engineering disciplines and it is rarely that companies have two of these experts residing under the same roof. Pipe Stress Engineers basically relied on support form Expansion Joint Experts on “as required basis” and called upon their knowledge only when needed. Thus, we have the situation where knowledge related to the design and construction of expansion joints sits with expansion joints manufacturing companies, which are totally separate and often remote entities in the piping design process. Even so, the ever present demand for techno-economical optimizations, points us to the following observations. The “Traditional method”, where Pipe Stress Engineer defines on his own the requirements for expansion joints and describes them in the technical specification for purchasing is, or should be, a theme of the past. This approach may be used only as a first attempt in search for the solution, but given that it never heads in the direction of achieving optimal techno-economical results, needs to be upgraded with additional steps.

Analysis of CCR Expansion Joints

2019 ◽  
Author(s):  
Sanjay Kaul ◽  
Rajpalsinh Gohil ◽  
Parul Bisharia ◽  
Apoorva Roy
Keyword(s):  
Hydrogen Atmosphere ◽  
Heat Of Reaction ◽  
Expansion Joint ◽  
Catalytic Reforming ◽  
Element Analysis ◽  
Expansion Joints ◽  
Thermal Movement ◽  
Temperature And Pressure ◽  
Design Calculations ◽  
Movement Test

Abstract The CCR (Continuous Catalytic Reforming) Platforming™ process is Honeywell UOP’s technology to convert low octane naphtha to high octane fuel or petrochemical feedstock such as aromatics. It is accomplished in a hydrogen atmosphere at elevated temperature and pressure across a platinum containing catalyst. The process flow is routed through heaters, blowers and coolers between reactors to maintain the heat of reaction. This article captures the procedure of selecting a suitable expansion joint for absorbing thermal movement between two important pieces of CCR equipment — the regeneration cooler and regeneration blower. It shows the design calculations of a universal hinged expansion joint operating at 0.14 MPa and 593°C in a pipe of 762mm diameter. The joint contains 5 single-ply INCOLOY 800H bellows with unreinforced convolutions. Design calculations of the expansion joint have been carried out using formulae prescribed in the Expansion Joints Manufacturers Association (EJMA) standard. Since it is difficult to quantify stresses using a movement test, the EJMA calculations have been verified against finite element analysis results of the bellows.

Design and Use of the Joint between Concrete-Filled Square Steel Tubular Special-Shaped Columns and Steel Beams

2012 ◽  
Vol 517 ◽  
pp. 870-874
Author(s):  
Xi Chen
Keyword(s):  
Green Building ◽  
Steel Beams ◽  
Loading Capacity ◽  
Sustainable Building ◽  
Environmentally Sustainable ◽  
The Public ◽  
Composite Frame ◽  
Force Transfer ◽  
Column Joint ◽  
Furniture Layout

Environmentally sustainable building construction has experienced significant growth during the past 10 years. The public is becoming more aware of the benefits of green construction, and green building is leading to changes in the way of owners, designers, contractors, and approach of the design, construction. Concrete-filled square steel tubular special shaped columns - steel beams residence installing efficient and light heat insulation wall is welcome for both owners and designers because of the columns having the same thickness with limb-filled walls, no-shocked indoor, easy to decoration and furniture layout, increasing in the actual using areas and saving carbon. The composite frame fully develops the merits of steel and concrete, and thus is reasonable and economical from both structural and construction viewpoints. The connection region as main force transfer component is key to the research of frame. Compared with the joint of ordinary reinforced concrete special shaped frame, the joint between concrete-filled square steel tubular special-shaped columns and steel beams has the advantage of better ductility , higher loading capacity, uncomplicated reinforcement disposing and convenient in construction. This paper discusses the features of concrete-filled square steel tubular special shaped columns - steel beams frame, and the design and use of beam-column joint. From the experimental study on seismic behavior of the joint, it is shown that the joint has strong energy dissipation capacity and higher loading capacity. So it is expected it could play an important role in residence structures. This study is helpful for further study of the design and use of the joint between concrete-filled square steel tubular special-shaped columns and steel beams.

Seismic Tests of Welded Moment Resisting Connections Made of Laser-Welded Stainless Steel Sections

2018 ◽  
Vol 763 ◽  
pp. 440-449
Author(s):  
Hafez Taheri ◽  
George Charles Clifton ◽  
Ping Sha Dong ◽  
Michail Karpenko ◽  
Gary M. Raftery ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Carbon Steel ◽  
Large Scale ◽  
Steel Structures ◽  
Steel Beams ◽  
Steel Connections ◽  
Steel Members ◽  
Moment Resisting ◽  
Steel Sections ◽  
Seismic Tests

Steel structures are well established as the preferred material for constructing seismic resisting systems in New Zealand and around the world. While the majority of steel framing is made of carbon steel, stainless steel is increasingly being considered for designing exposed steel structures. Because of significant differences in the mechanical properties between the two materials, seismic resisting system design rules for connections between carbon steel members may not be applicable, at least without modification, to connections between stainless steel members. This study has investigated the seismic performance of welded T-shaped beam-column moment resisting connections made of structural stainless steel beams and columns manufactured by laser welding. The paper included the results of three large-scale T-shaped specimens, of varying sizes, subjected to seismic loads. The grade of laser-fused stainless steel was 304 L and its specification was according to ASTM A276. The sections were subject to the seismic tests in accordance with the SAC protocol given in ANSI/AISC 341-10. The results shows substantial amount of energy dissipation by welded moment resisting stainless steel connections along with a high ductility capability and dependable behaviour in the inelastic range.

Application Research of Method of Noumenon Sampling Detection in Strength Test on Structural Concrete

2012 ◽  
Vol 512-515 ◽  
pp. 3011-3016
Author(s):  
Guo Zhi Zhang ◽  
Liang Guo
Keyword(s):  
Conversion Coefficient ◽  
Concrete Strength ◽  
Strength Test ◽  
Correction Coefficient ◽  
Application Research ◽  
Structural Concrete ◽  
Detection Technology ◽  
Test Result

Noumenon sampling, a new detection technology for strength of structural concrete, is proposed.The conversion relationship between the strength of noumenon sampling specimen and the strength of standard maintenance specimen was explored by correction coefficient and regression analysis．the conversion coefficient for concrete strength between the standard curing specimen and the structural concrete was1.08, which is less than the specification of conversion coefficient(1. 10); therefore, the test result by noumenon sampling is more accurate and reliable.

Sign in / Sign up

Export Citation Format

Share Document