Load transfer of circular reinforced composite dowel connector: a comparison of existing analytical equations

in ce/papers (2023, September 12), 6(3-4), 101-106

The effectiveness of headed studs for shear transfer in the steel-concrete interface of composite columns is questionable when important load needs to be transferred. Circular reinforced composite dowel ... [more ▼]

The effectiveness of headed studs for shear transfer in the steel-concrete interface of composite columns is questionable when important load needs to be transferred. Circular reinforced composite dowel (CRCD) connectors are known for their high initial stiffness and significant load-bearing capacity. This paper presents the different types of CRCD connectors and the available analytical equations to determine their shear resistance, as well as a database of 52 experimental specimens to study their performance. The results show that the equations developed by Wang et al.2014, He et al.2016and Zhao et al.2016 provided the best performance, with 76% of the predictions falling within the error bounds of +/-15%. Further research is recommended to understand the behavior of CRCD connectors on H-shaped steel profiles and to develop analytical equations to calculate their resistance. [less ▲]

Structural Reliability Assessment of Composite Columns in Steel and Concrete using Non-linear Finite Element Analysis

Poster (2023, June 08)

In Eurocode 0, the ultimate limit state is related to the structural failure (collapse) of a part e.g., column, beam, foundation or the entire structure. Mathematically, this can be expressed in terms of ... [more ▼]

In Eurocode 0, the ultimate limit state is related to the structural failure (collapse) of a part e.g., column, beam, foundation or the entire structure. Mathematically, this can be expressed in terms of limit-state function g(x) = R(x) – S(x), and the probability of failure as Pf = P [g(x)<0] where R is the resistance of the structure and S is the loading part. In Eurocode 0, the target reliability index β for reference period of 50 years is β=3.8 which represents the probability of failure of 0.1%. The probability of failure is related to reliability index β as Pf=Φ(−β), where Φ is cumulative distribution function of the standard normal distribution. In finite element analysis (FEM), the input parameters e.g., geometry of the structure, materials, loads, and other structural properties are deterministic, while the stochastic finite element analysis is an extension of FEM, which allows variation of these parameter as random variable. In this study the stochastic finite element analyses for composite columns in steel and concrete were performed using OpenSeesPy and QuoFEM. First the deterministic model was developed in OpenSeesPy and validated with experimental results and ABAQUS then, the model is transformed in probabilistic one using QuoFEM which is an open-source research application software with focus on providing uncertainty qualification methods. To generate sampling of the random variables, The Latin Hypercube Sampling (LHS) and Monte Carlo (MS) were used. The results from parametric SFEM analyses were compared with safety level provided by Eurocode 4 according to general and simplified method for design of composite columns in steel and concrete under compressive axial load. [less ▲]

Sustainability assessment of a novel reusable and demountable steel-concrete composite floor system

in ECPPM 2022 - eWork and eBusiness in Architecture, Engineering and Construction 2022 (2023)

Raw materials extraction, production of components, transportation and reverse logistics activities that run in the construction sector are constantly depleting the available global resources ... [more ▼]

Raw materials extraction, production of components, transportation and reverse logistics activities that run in the construction sector are constantly depleting the available global resources. Sustainability of the construction industry and its ability to adopt to the principles of circular economy is under question. This paper addresses these questions through the introduction of a novel reusable steel-concrete composite floor system. Its reuse potential is evaluated through comparative BIM-based Life Cycle Analysis with contemporary systems. [less ▲]

Steel-fibre reinforced concrete in compo-site structures as a mean to increase re-sistance and ductility

in Stahlbau (2022), 91(12), 801-811

Steel-fibre reinforced concrete is a well-known material used for decades for industrial floorings, shot-crete, or other specific applications. Its use is now spreading in structural applications as a ... [more ▼]

Steel-fibre reinforced concrete is a well-known material used for decades for industrial floorings, shot-crete, or other specific applications. Its use is now spreading in structural applications as a complement or a substitute for conventional bar-reinforced concrete since the normative framework is ready to provide design approaches for several concrete applications. Nevertheless, some adaptations are needed for implementing steel-fibre reinforced concrete in the design approach for steel-concrete composite struc-tures whereby complementary aspects need to be considered. In this field, besides the increase of tensile properties and durability of the concrete member, a very important contribution may be given by the in-crease of the concrete ductility in compression. This property is conferred by the steel fibres which pro-vide a confinement effect increasing the plastic damage that the concrete matrix can absorb. If this prop-erty is widely accepted, its benefits are limited for the design of conventional concrete sections. Con-versely, for composite sections, the possibility to reach higher strains in compression means ensuring full exploitation of the strength capacity of structural steel. Besides reaching an optimization of already in-use cross-sections, this new material combination enhances the use of higher structural steel strengths in composite structures. [less ▲]

Determination of Slip Factor between CNC-Cut Serrated Surfaces of S355J2 Grade Steel Plates

in Buildings (2022), 12(995),

Determination of Slip Factor between CNC-Cut Serrated Surfaces of S355J2 Grade Steel Plates by Taygun Fırat Yolaçan and Markus SchäferStructural joint configurations realized with serrated steel surfaces ... [more ▼]

Determination of Slip Factor between CNC-Cut Serrated Surfaces of S355J2 Grade Steel Plates by Taygun Fırat Yolaçan and Markus SchäferStructural joint configurations realized with serrated steel surfaces have started to be used in the construction fields to assemble the primary and the secondary structural members of civil engineering structures. The main advantages of these joint configurations rely on their flexibility to accommodate construction tolerances and their slip-resistant load-bearing mechanism against dynamic loading conditions. Therefore, it is important to reliably establish the characteristic value of the friction coefficient or in other words the slip factor between the serrated steel surfaces to design reliable slip-resistant connections. In this study, the characteristic slip factor between the CNC-cut serrated surfaces prepared from S355J2 grade steel plates is determined to investigate the impact of the CNC-cutting procedure on the slip-resistant load-bearing behaviour of steel-to-steel interfaces. Five experimental tests were performed according to EN1090-2, Annex G. The results are presented as the load-slip curves, variation of the bolt pre-tension load level, nominal and actual slip factors for the tested configuration of the CNC-cut serrated steel-to-steel interface [less ▲]

Slim-Floor Bauweise – Bemessung und Ausführung

Presentation (2022, March 29)

Integration of design for shallow floor beam in prEN1994-1-1; design and construction for shallow floor construction

Bridge damage assessment based on static and dynamic flexibility matrices

in Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability (2022)

Being an indispensable part of transportation systems, Structural Health Monitoring (SHM) of bridges has been increasingly studied. Various SHM techniques not only enhance reliability and safety but also ... [more ▼]

Being an indispensable part of transportation systems, Structural Health Monitoring (SHM) of bridges has been increasingly studied. Various SHM techniques not only enhance reliability and safety but also reduce maintenance costs. Various bridge deteriorations change the structural properties, such as flexibility and stiffness. Therefore, damage assessment can be achieved by monitoring the structural matrices of bridges and tracking the deviations from the healthy-state or reference data. This paper focuses on damage detection of a prestressed concrete beam from a demolished bridge based on the flexibility matrix. The dynamic and static flexibility matrices are calculated numerically and experimentally when the beam is undamaged. The simulated and measured static flexibility matrices differ by only about 5 %. Additionally, the numerical dynamic flexibility matrix is strongly correlated with static results. The findings of this study can be employed as a basis for future damage detection applications when artificial damage is introduced. [less ▲]

Draft for second generation of prEN 1994-1-1, November 2021

Report (2021)

Development of second generation for Eurocode 4, part 1: prEN 1994-1-1: November 2021- Draft + Respons on comments

Non-linear Analysis of Circular Composite Columns

in Burgess, Ian (Ed.) Special Issue: Proceedings of Eurosteel 2021: Sheffield - Steel's coming home (2021, September)

Composite columns provide many advantages for the application in multi-story and high-rise buildings. However, EN 1994-1-1 does not provide rules for the design of circular concrete sections with fully ... [more ▼]

Composite columns provide many advantages for the application in multi-story and high-rise buildings. However, EN 1994-1-1 does not provide rules for the design of circular concrete sections with fully encased steel profiles according to the simplified methods. Normally, the simplified method for the design of composite columns is based on a normal force-moment interaction diagram which assumes plastic cross-section resistance. However, the moment resistance is to be reduced by a reduction factor M, considering among other the difference between strain-limited and plastic moment resistance. This reduction factor is developed and calibrated for composite compression members with concrete encased sections, partially encased sections and concrete filled rectangular and circular tubes. Comparison of plastic moment resistance to results based on strain limitation show that the application for circular section with encased steel section but without a steel tube may lead to unsafe results. The paper discusses different approaches for the determination of the N-M Interaction curve and the design on cross-section level. The results obtained from these methods are then compared to each other for different dimensions of cross-sections of circular columns; and for different ratios of reinforcements, various steel grades and for normal and high strength concretes. Furthermore, the investigation focuses on the validation of the reduction factor alfa_M and shows for which section types the values according to Eurocode 4 cannot be applied. [less ▲]

Behavior of downstand simply supported steel-concrete composite beam applying friction based demountable shear connection

in Burgess, Ian (Ed.) Special Issue: Proceedings of Eurosteel 2021: Sheffield - Steel's coming home (2021, September)

In order to improve sustainability of composite structures and promote the principles of circular economy in construction industry, novel demountable shear connector based on the frictional behavior was ... [more ▼]

In order to improve sustainability of composite structures and promote the principles of circular economy in construction industry, novel demountable shear connector based on the frictional behavior was developed within the framework of Work package 2 of parent project ECON4SD (Eco Construction for Sustainable Development) at the University of Luxembourg. The demountable composite floor system is composed out of modular concrete one-way solid slabs with equidistantly embedded Halfen HTA-CE rail channels, double symmetric steel I section and demountable connector device assembly based on HV high strength structural bolts for preloading that provides the demountable shear connection. In this paper trilinear behavior model is proposed for the force-slip behavior of aforementioned connector device complying to the results of the push test experimental campaign and the results of FEA simulations. Afterwards, parametric study is performed on the range of simply supported composite beams in propped and unpropped condition under uniformly distributed load applying the aforementioned shear connection validating the predictability of the composite beam bending behavior in accordance with the rules of EN 1994-1-1. [less ▲]