检索结果-内蒙古大学图书馆

Experimental Assessment of Stainless and Carbon Steel Double-Skin Tubular Stub Columns Filled with Recycled Aggregate Concrete

引用

ce/papers 2021年第2-4期4卷 764-771页

作者： Castanheira, Deborah S. de Lima, Luciano R. O. Vellasco, Pedro C. G. da S. Cashell, Katherine A. Gardner, Leroy PGECIV - Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Department of Civil and Environmental Engineering Imperial College London London United Kingdom Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil Department of Civil and Environmental Engineering Brunel University London United Kingdom

This paper presents an experimental study into the behaviour of concrete filled double skin tubular (CFDST) stub columns. A total of eight axial compression tests were carried out, half of which were filled with conventional concrete and the remainder had recycled aggregate concrete. The columns were circular in cross-section and comprised an austenitic stainless steel outer tube and a carbon steel inner tube, of varying dimensions. Accordingly, hollow ratios of 0.67 and 0.55 were considered. The recycled coarse aggregate was made by crushing test specimens from a previous research project. A replacement ratio of 50% was adopted in these tests. Both the natural coarse aggregates and the recycled aggregates had a maximum diameter of 9.5 mm. During the tests, similar structural behaviour and failure modes were observed between the columns with conventional and recycled aggregate concrete, and the faiure modes were identical. The experimental results are compared with available design procedures and it is ultimately shown that using recycled aggregate concrete rather than regular concrete in CFDST stub columns does not have a significant effect on the performance. © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Compression testing

来源：评论

学校读者我要写书评

暂无评论

Assessing the Performance of Eggshell Ash as a Sustainable Bitumen Modifier

SSRN

引用

SSRN 2023年

作者： Syammaun, Tamalkhani Husaini, Husaini Abdullah, Abdullah Isya, Muhammad Rachman, Firmansyah Doctoral Program School of Engineering Post Graduate Program Universitas Syiah Kuala Banda Aceh23111 Indonesia Department of Civil Engineering Universitas Muhammadiyah Aceh Banda Aceh23123 Indonesia Department of Mechanical Engineering Universitas Syiah Kuala Banda Aceh23111 Indonesia Department of Civil Engineering Universitas Syiah Kuala Banda Aceh23111 Indonesia

The disposal of eggshells in landfills presents an ongoing global environmental issue that demands immediate attention. However, a promising solution lies in utilizing eggshells as modifiers in bitumen binders, offering a sustainable approach to alleviating this burden. This study focuses on crushing eggshells to produce eggshell ash, which is then explored as a potential modifier in bitumen binders. The objective is to evaluate the properties of modified bitumen binders incorporating eggshell waste sourced from the food industry and examine their application in bitumen engineering. Employing a 60/70 penetration-grade asphalt binder as the research foundation, the optimal weight percentage of eggshell ash in the bitumen is determined, considering four levels (5%, 7%, 10%, and 12%) and two different heating temperatures (100°C and 200°C). Several tests are conducted to comprehensively evaluate the eggshell ash, including SEM-EDS and FTIR analyses, providing valuable technical insights into its properties. Additionally, dynamic shear rheometer (DSR) measurements are employed to analyze the characteristics of the bitumen incorporating eggshell ash. The primary oxide group present in the eggshell ash is calcium carbonate (CaCO3). Notably, higher concentrations of eggshell ash enhance the resistance of bitumen binders to high temperatures, as indicated by the penetration index results. Furthermore, DSR testing reveals that the addition of eggshell ash significantly increases the rigidity of the bitumen binders, resulting in improved resistance to deformation. © 2023, The Authors. All rights reserved.

关键词： Binders

来源：评论

学校读者我要写书评

暂无评论

12.07: Numerical assessment of stayed austenitic steel columns

引用

ce/papers 2017年第2-3期1卷 3519-3526页

作者： Ribeiro, Danielle M. da S. Vellasco, Pedro C. G. de Araujo, Ricardo R. de Lima, Luciano R. O. da Silva, André T. PGECIV – Civil Engineering Post-Graduate Program State University of Rio de Janeiro – UERJ Brazil Structural Engineering Department State University of Rio de Janeiro – UERJ Brazil Civil Engineering Department Federal Center for Technologic Education Celso Suckow da Fonseca – CEFET/RJ Brazil

The use of prestressed steel stayed columns systems in construction has numerous advantages related to its light weight, load bearing capacity and assembly process flexibility. A practical application of these structural systems could be recently observed in Brazil for the erection of the Rock in Rio III world stage. In this event the use of prestressed stayed carbon steel columns were used for temporary shoring, optimizing the erection sequence. The main stage had a 82 meters span with a 40 m clear height and a 4500 m2 area. Two stayed column were used, both with a 20 m length. Up to the present the majority of investigations of these stayed systems have been focused on carbon steel columns. In view of these facts the present paper aimed to present an investigation of the structural behaviour of columns made with the austenitic stainless steel. Numerical models were developed in the Ansys software, focusing on the structural system load carrying capacity and the optimal level of prestress to be used. The optimal level of prestress to be used was also determined considering the influence of initial imperfections. The results confirmed that the use of prestress in the cables significantly enhance the ultimate loads and ductility capacity of the columns. © Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Austenitic stainless steel

来源：评论

学校读者我要写书评

暂无评论

Numerical evaluation of tubular perfobond shear connectors

引用

ce/papers 2021年第2-4期4卷 666-674页

作者： Souza, Keila L. da Silva, André T. Henriques, José Vellasco, Pedro C. G. Rodrigues, Monique C. PGECIV - Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil Construction Engineering Research Group IIW Faculty Hasselt University Belgium

Composite structures have been applied more frequently because they are an economical structural solution with excellent structural performance. The interaction is guaranteed with the use of elements that transfer the forces between these two materials. The most common mechanical connections between steel and concrete are made through shear connectors. Some of the connectors types used nowadays are stud bolt, U-profiles, Crestbond, Perfobond and T-Perfobond. Eurocode 4 prescribes that a connector has to possess a minimal ductility, one of the main requirements to shear connectors. The current Perfobond presents excellent resistant capacity, but low deformation capacity, contradicting what is prescribed by the code. This paper aims to study a Tubular Perforbond connector by analyzing the parameters that can influence its resistance and deformation capacity, applying FEM through Abaqus software, to simulate the composite structural, mechanical behaviour. When comparing the Tubular Perfobond connector with the Perfobond connector, it was possible to observe that the tubular connectors presented a substantial deformation capacity after peak load, while attending the connector ductility requirements. The use of Tubular connectors also decreased the concrete crushing propagation. © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Nonlinear analysis

来源：评论

学校读者我要写书评

暂无评论

Influence of bearing coefficient in cold-formed stainless steel bolted connection

引用

ce/papers 2021年第2-4期4卷 148-155页

作者： Sobrinho, Kelvin da Silva, André T. Rodrigues, Monique C. Henriques, José A. Lima, Luciano R. da Vellasco, Pedro C. G. PGECIV - Civil Engineering Post-Graduate Program UERJ – State University of Rio de Janeiro Brazil Structural Engineering Department UERJ – State University of Rio de Janeiro Brazil Construction Engineering Research Group IIW Faculty Hasselt University Belgium

The connections play an important role in the overall behaviour of the structures. Therefore an adequate structural design taking into account both safe and economic criterion is necessary. The structural design of stainless steel bolted connections using actual codes can provide inadequate design capacity mainly due to the use of similar rules based on analogies from mild carbon structures. Thus, the purpose of this paper is to evaluate the structural response of stainless bolted connections considering the steel grade austenitic 304. Experimental and numerical analyses have been carried out considering bolted connection under bearing failure. In details, the study cases were subjected to two shear planes with thin-plate and thick-plate. In these cases, the occurrence of curling failures is possible. A detailed study involving the geometric parameters adopted by design equations of bolted stainless steel connections was made. The outcomes showed a reduction of the ultimate capacity characterised by out-plane deformation. In addition, the current codes led to significant difference when compared to both experimental and numerical results. © 2021 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Structural design

来源：评论

学校读者我要写书评

暂无评论

Influence of the Corrosion Degree of Hot-Dipped Galvanized Reinforcements on its Bond Strength to Concrete

SSRN

引用

SSRN 2024年

作者： da Fonsêca, Márcia Suzanna Dutra Abreu Borges Meira, Gibson Rocha The Civil and Environmental Engineering of Federal University of Paraíba João Pessoa Brazil The Federal Institute of Education Science and Technology of Paraíba João Pessoa Brazil The Civil and Environmental Engineering Post-graduate Program of Federal University of Paraíba João Pessoa Brazil

This work studies the behavior of hot-dipped galvanized steel against chloride corrosion and its effect on its bond strength to concrete. Two steel diameters were adopted and bond strength was assessed using a standardized pull-out test, followed by measuring different degrees of corrosion. The results show that the initial corrosion of hot-dipped galvanized steel, due to the high alkalinity of fresh concrete, does not affect the structural performance of reinforced concrete and that galvanized steel has superior bond strength to concrete than non-galvanized steel for small corrosion rates. However, it decreases as the corrosion degree significantly increases. © 2024, The Authors. All rights reserved.

关键词： Reinforced concrete

来源：评论

学校读者我要写书评

暂无评论

NUMERICAL ANALYSIS WITH IMPLEMENTATION OF DAMAGE TO STAINLESS STEEL BOLTED CONNECTIONS SUBJECTED TO SHEAR LOAD

引用

ce/papers 2019年第5-6期3卷 426-435页

作者： Sobrinho, Kelvin P. Silva, André T. Rodrigues, Monique C. Henriques, José A. G. Vellasco, Pedro C. G. S. Lima, Luciano R. O. PGECIV – Post-Graduate Program in Civil Eng. State University of Rio de Janeiro – UERJ Brazil Structural Engineering Department State University of Rio de Janeiro – UERJ Brazil Faculty of Engineering Technology University Hasselt – Hasselt Belgium

In this paper, an experimental and numerical study were developed to evaluate the behavior of stainless steel bolted connections subjected to shear load until rupture, in which austenitic stainless steel 304 was used. In order to determine the material behavior, tensile coupon tests were performed. The numerical model was developed in Abaqus finite element program using dynamic explicit analysis and solid elements (C3D8) with an elastic-plastic stress-strain curve with strain hardening and damage criteria. Additionally, a comparison of the results with the recommendations given by the current standards for stainless steel structures was also accomplished. © 2020 Ernst & Sohn Verlag für Architektur und technische Wissenschaften GmbH & Co. KG, Berlin.

关键词： Strain hardening

来源：评论

学校读者我要写书评

暂无评论

Design alternative on peat soil

引用

IOP Conference Series: Materials Science and engineering 2020年第1期1007卷

作者： Vicky Muroby Chaidir Anwar Makarim Civil Engineering Post-graduate Program Faculty of Engineering Universitas Tarumanagara

Construction on peat soil has its own difficulty and challenge due to its properties of low shear strength, high compressibility, high water content, and flammable material. Indonesia ranked 4th on peat land area around the world after Canada, Russia, and United States. Based on recent mapping, peat land covers 14,9 million hectare in Indonesia. This paper presents the finding from literature studies regarding peat soil, construction on peat soil, case studies for road infrastructure construction on peat soil at West Borneo, Indonesia, and provide analysis and recommendation for the problems faced. Construction on peat soil requires special attention, especially on the design and execution. In the event where construction must be performed on a peatland which thickness is < 3m, the approach recommended is peat removal and replacement. If the peat thickness is 3-10 m, adopt the preloading, construction with vertical and sand drain, lightweight fills, surface mattress, stone column, etc. If the peat thickness is < 10m, use pile as foundation. Unit price contract is preferable over lumpsum contract due to the high uncertainties of peat soil. Environment impact due to construction on peat soil need to be accounted for, also the risk of peat fires need to be considered if dewatering used.

关键词：

来源：评论

学校读者我要写书评

暂无评论

On the delay factors of the private construction projects in Medan city

引用

IOP Conference Series: Earth and Environmental Science 2018年第1期126卷

作者： A. Perwira Mulia Tarigan Subroto Teaching Staff Post Graduate Study Program of Civil Engineering Universitas Sumatera Utara Former Graduate Student Post Graduate Study Program of Civil Engineering Universitas Sumatera Utara

The delay in construction projects undertaken by contractors is impeding the economic growth of a region. Medan city which is one of the big cities in Indonesia is suffering from it. This study aims to identify the dominant factors causing delays in construction projects conducted by private contractors. The interview method with questionnaires is used to involve 20 contractors, 10 consultants, and 10 owner representatives in the study. From the 45 identified factors causing delays, the highest ranking is the change of work demand by the project owners with 71.84% importance index.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Numerical analysis of the influence of the contact boundary condition and specimen geometry on concrete compressive strength

引用

Procedia Structural Integrity 2023年 47卷 261-267页

作者： Caroline Bremm Luísa Inda Leandro Ferreira Friedrich Sabrina Vantadori Ignacio Iturrioz Luis Kosteski Engineering Post Graduation Program Federal University of Pampa Av. Tiaraju 810 Alegrete 97546-550 Brazil Civil Engineering Graduate Program Federal University of Pampa Av. Tiaraju 810 Alegrete 97546-550 Brazil Program of Mechanical Pos-Graduation Federal University of Rio Grande do Sul Sarmento Leite 425 Porto Alegre 90040-060 Brazil Department of Engineering & Architecture University of Parma Parco Area delle Scienze 181/A 43124 Parma Italy

In the present paper, the influence of the contact boundary condition and specimen geometry on the concrete compressive strength is numerically investigated by using a version of the Lattice Discrete Element Method (LDEM), implemented on Abaqus/Explicit. More precisely, two types of contact boundary conditions are considered and, for each of them, three different slenderness levels (height/width ratio - h/b) are analyzed (that is, h/b = 0.5, 1.0, and 2.0) by considering a square cross-section. Moreover, for h/b = 2.0, a circular cross-section is also examined. Two models are developed: one by using the LDEM and the other by using a hybrid model, combining Finite Elements and LDEs. The results show that both the boundary conditions and the sample geometry influence the axial compressive strength.

关键词： Abaqus concrete compressive strength Lattice Discrete Element Method (LDEM)

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：