- Influence of water binder ratio on high performance concrete
- P.N. Raghunath ; N. Seshadri-Sekhar
- The Open Construction and Building Technology Journal, 8, 18-21
- Book Title / Journal:
- Year: 2014 , Volume: , Series:
- Structure types ; Concrete structures
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- Weak-Axis Behavior of Wide Flange Columns Subjected to Blast
- N. Krishnappa ; M. Bruneau
- Book Title / Journal: ASCE J. Structural Engineering
- Year: 2014 , Volume: 140 , Series:
- Structure types ; Steel structures
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- Shear transfer along interfaces: constitutive laws
- K. Trezos ; E. Vintzileou ; V. Palieraki
- Book Title / Journal: 2nd European Conference on Earthquake Engineering and Seismology, Istanbul, Turkey
- Year: 2014 , Volume: , Series:
- Structure types ; Concrete structures
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- A fire resistance design method for thin-walled steel studs in wall panel constructions exposed to parametric fires
- Y.C. Wang ; A. Shahbazian
- Book Title / Journal: Thin-Walled Structures, 77, 67–76
- Year: 2014 , Volume: , Series:
- Structure types ; Steel structures
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- Mechanical properties of brick masonry with different types of bonds
- C. Cuadra ; T. Taguchi
- Book Title / Journal: 2nd European Conference on Earthquake Engineering and Seismology, Istanbul, Turkey
- Year: 2014 , Volume: , Series:
- Structure types ; Masonry Structures
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- Influence of longitudinal reinforcement layouts on RC wall performance
- S. Sritharan ; K. Beyer ; R. Constantin ; J. Almeida ; A. Rosso
- Book Title / Journal: 2nd European Conference on Earthquake Engineering and Seismology, Istanbul, Turkey
- Year: 2014 , Volume: , Series:
- Structure types ; Concrete structures
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- Tensile and cyclic behavior of corroded 10mm deformed steel reinforcement-preliminary results
- A Palermo ; A. Scott ; K. Andisheh
- Book Title / Journal: 2nd European Conference on Earthquake Engineering and Seismology, Istanbul, Turkey
- Year: 2014 , Volume: , Series:
- Structure types ; Concrete structures
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- Advances in design requirements for Buckling Restrained Braced frames
- K.S. Robinson
- Book Title / Journal: New Zealand Society for Earthquake Engineering (NZSEE) Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Structure types ; Steel structures
- Keywords: Buckling Restrained Braced frames ; design requirements
- Description
- Although buckling restrained braces (BRB) have now been a codified system in the US for over five years and have been used in design for much longer, the
system is still relatively new in New Zealand. BRB’s are now entering their second US code cycle with the AISC Seismic Provisions for Structural Steel Buildings, AISC 341-10, which has introduced significant changes. In addition, several key issues of current research will be discussed that are contributing to the next set of code requirements for 2016. These new changes will be highlighted along with methods to effectively design Buckling Restrained Braced Frames (BRBF) using New Zealand codes. The latest innovative uses for BRBs will also be discussed, including applications to alleviate
building pounding concerns when seismic joints are of limited size, many different configurations possible for retrofit construction, ideas for high rise applications, and other unique applications.
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- Review of buckling restrained brace design and behaviour
- A.S. Jones ; C-L Lee ; G.A. MacRae ; G.C. Clifton
- Book Title / Journal: New Zealand Society for Earthquake Engineering (NZSEE) Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Structure types ; Steel structures
- Keywords: Buckling restrained braces ; brace design
- Description
- Buckling restrained braces (BRBs) have become a popular alternative to traditional bracing in seismic loading due to their ability to develop full and balanced hysteresis loops resulting in similar tension and compression capacities. However, research internationally for the design and behaviour of BRB compositional elements is still in the infancy stage, with intellectual property rights by commercial providers within America and Asia limiting the available research.
This paper considers the history and development of BRBs (steel-concrete and steel-steel), current design practice, areas for further development and forthcoming research to be carried out that the University of Canterbury. The outcomes of this research which consider the sensitivity in BRB member design aims to equip engineers with an understanding of BRBs but also the ability to design BRBs without the need for testing verification.
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- Preliminary estimation of reduction factors in mechanical properties of steel reinforcement due to pitting simulated corrosion
- K. Andisheh ; A. Scott ; A Palermo
- Book Title / Journal: New Zealand Society for Earthquake Engineering (NZSEE) Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Structure types ; Concrete structures
- Keywords: Corrosion ; steel structures
- Description
- In recent years, growing attention has been given to the effects of corrosion on reinforced concrete structures. Marine environment and de-icing salt are two causes chloride-induced corrosion. Basically, there are two types of steel reinforcement
corrosion called general and pitting corrosion. In real corroded reinforced concrete (RC) structures, a mix of the general and pitting corrosion usually takes place. Corrosion decreases the mechanical characteristics of steel reinforcing.
In this study, reduction factors of mechanical properties of steel reinforcement have been estimated through experimental monotonic tensile tests to take into consideration of eccentricity caused by pitting corrosion. Reduction factors have been defined to estimate the effect of corrosion on the reduction in mechanical properties of corroded steel bars. The reduction factors indicate the percentage reduction in the mechanical properties for 1% loss of cross-section area of steel reinforcement.
To meet this aim, pitting corrosion has been simulated by mechanically removing a portion of the cross section form 10mm, steel reinforcement. The reduction factors in terms of yield stress, ultimate stress, module of elasticity and elongation have been estimated from monotonic tensile tests. The relevant deterioration models have been
developed based on the experimental results, and have been used for section-level
analysis of a reinforced concrete bridge pier. The results of section-level analysis show degradation in moment-curvature and force-displacement of the corroded RC bridge pier due to pitting corrosion.
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- Composite slab effects on beam-column subassemblies: Further development
- T. Chaudhari ; G. MacRae ; D. Bull ; G- Chase ; M. Hobbs ; C. Clifton ; S. Hicks
- Book Title / Journal: New Zealand Society for Earthquake Engineering - Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Structure types ; Composite structures
- Keywords: composite slabs
- Description
- Composite slab construction is gaining popularity in New Zealand. These slabs may influence beam column joint subassemblies as they are exposed to earthquakeinduced shaking. However, several design issues with composite slabs need to be addressed so that they can be used to their full advantage in design. These relate to considering the effect of the slab on the beam design strength, the likely statistical variation of the beam and slab under strong seismic shocks that will affect the column joint demand, and the resistance of the panel zone.
In this paper, experimental test setups are described which consider slab isolation, beam
overstrength, full depth slab around the column, low damage connection, and demand on the panel zone. A new concept of slab confinement using a shear key will be presented to form a force transfer mechanism to avoid failure of concrete either in crushing or spalling. Also the development of a non-prying sliding hinge joint low damage connection and its performance with composite slabs is discussed. The outcome of this
will be useful to develop simple design recommendations for the New Zealand steel
standard.
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- Seismic design of composite metal deck and concrete-filled diaphragms - A discussion paper
- K.A. Cowie ; A.J. Fussell ; G.C. Clifton ; G.A. MacRae ; S.J. Hicks
- Book Title / Journal: New Zealand Society for Earthquake Engineering - Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Structure types ; Composite structures
- Keywords: composite deck ; diaphragm
- Description
- One of the most neglected elements in the design of buildings is the horizontal floor diaphragm and its interaction with the lateral load resisting systems. Most multi-story structures depend on the floor slab and roof systems to act as horizontal diaphragms to collect and distribute the lateral loads to the vertical framing members, which provide the overall structural stability.
In steel structures, floor diaphragms are most commonly constructed using composite steel deck with concrete fill, although other systems may also be used. Somewhat surprisingly, given the importance of diaphragms to the overall building response, there is no universally agreed design procedure for determining the diaphragm actions and distribution into the seismic-resisting systems. In addition, the specific issues related to beam design for members collecting lateral loads in composite floor systems has gone largely undocumented.
This discussion paper presents a suggested method in determining the design diaphragm actions at a given floor level, how to proportion their transfer into the seismic resisting systems and how to design and detail the supporting beams/composite metal deck for these actions.
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- Non-destructive method to investigate the hardness - plastic strain relationship in cyclically deformed structural steel elements
- H. Nashid ; W.G. Ferguson ; G.C. Clifton ; M. Hodgson ; M- Battley ; C. Seal ; J.H. Choi
- Book Title / Journal: New Zealand Society for Earthquake Engineering (NZSEE) Annual Technical Conference
- Year: 2014 , Volume: , Series:
- Structure types ; Steel structures ; Non Destructive Testing
- Keywords: steel elements ; non-destructive method
- Description
- A non-destructive hardness testing method is being developed to determine plastic strain in steel elements that have been subjected to inelastic seismic loading. The focus of this study is on the active links of eccentrically braced frames (EBFs). The 2010/2011 Christchurch earthquake series, especially the very intense February 22 shaking, was the first earthquake worldwide to push complete EBF systems into their inelastic state, generating a moderate to high level of plastic strain in EBF active links for a range of buildings from 3 to 23 storeys in height. Plastic deformation was confined to the active links. This raised two important questions: 1) what was the extent of plastic deformation; and 2) what effect does that have on post-earthquake steel properties? To answer these questions a range of actions are being taken. A non-destructive hardness test method is being developed to determine a relationship between hardness and plastic strain in active link beams. Active links from the earthquake affected, 23-storey Pacific Tower building in Christchurch has been hardness and material property tested to determine the changes in the steel, and cyclic testing of active links to defined levels of inelastic demand is underway. Test results to date show clear evidence that the hardness based method is able to give a good relationship between hardness measurements and plastic strain. This paper presents recent significant findings from this project. Principal of these is the discovery that hot rolled steel tested beams, all carry manufacturing induced plastic strains, in regions of the webs, of up to 5%. It is the intention of the overall research project, to establish a robust relationship between measured hardness and plastic strain demand in cyclically deformed steel elements and a comprehensive guideline to assess commonly used seismic-resisting systems will be adopted.
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- Studies on the in-plane shear response of confined masonry shear walls
- T. Janaraj
- Book Title / Journal: PhD thesis, Queensland University of Technology, Australia
- Year: 2014 , Volume: , Series:
- Structure types ; Masonry Structures
- Description
- The prime aim of this research project is to evaluate the performance of confined masonry walls under in-plane shear with a view to contributing to the national masonry design standard through a set of design clauses. This aim stems from the criticisms of the current provisions of the in-plane shear capacity equations in the Australian Masonry Standard AS3700 (2011) being highly non-conservative. This PhD thesis is an attempt to address this gap in the knowledge through systematic investigation of the key parameters that affects the in-plane shear strength of the masonry walls through laboratory experiments and extensive finite element analyses.
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- Development of thin layer mortared concrete masonry
- J. Thamboo
- Book Title / Journal: PhD thesis, Queensland University of Technology, Australia
- Year: 2014 , Volume: , Series:
- Structure types ; Masonry Structures
- Description
- The thin layer mortared concrete masonry is an emerging construction system. Therefore,
there exists a need for data on the response of this form of masonry construction subject to
various states of stress so that thin layer mortared masonry could be practiced as a legitimate
structural system. This PhD aims at developing datasets for thin layer mortared concrete
masonry through systematic experimental and numerical studies.
A range of concrete units (Solid, full size hollow and half scale) with varying dimensions and
sizes have been used to construct thin layer mortared concrete masonry specimens to truly
reflect the field practices. A micro finite element model incorporating the contact surfaces
between the units and mortar layers has been used to link the data from specimens of
different constructs...
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