- Modeling of Masonry Infill Panels for Dynamic Analysis
- W. Basiouny ; A. Ghobarah
- Book Title / Journal: 14th World Conference on Earthquake Engineering
- Year: 2008 , Volume: , Series:
- Structure types ; Masonry Structures ; Earthquake engineering
- Keywords: Infilled frames ; Reinforced Concrete ; Finite elements
- Description
- The performance of reinforced concrete (RC) infilled frames during earthquakes shows that the behaviour is very much dependent on the performance and mode of failure of the infill masonry walls. The concrete frame may fail as a consequence of the infill wall failure before reaching the bare frame load resistance levels. Even though frameinfill interaction has sometimes led to undesirable structural performance, recent studies have shown that a properly designed infilled frame can be superior to a bare frame in terms of stiffness, strength, and energy dissipation. The objective of this paper is to present a new finite element model based on prescribed failure planes in the infill panels, where Drucker-Prager failure criterion is used to simulate the behaviour of masonry. Interface elements are
used to describe the behaviour of masonry panel along the prescribed failure planes. The elasto-plastic behaviour of mortar and cracked masonry along the failure planes are considered in the analysis. The proposed model was incorporated in a generic nonlinear structural analysis program for static and dynamic analysis of masonry infilled reinforced concrete frames. Simulations of experimental force-deformation behaviour of large scale infilled frame are performed to validate the proposed model.
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- Three-Dimensional Seismic Analysis of Masonry Combined Systems
- N. Augenti ; F. Parisi
- Book Title / Journal: 14th World Conference on Earthquake Engineering
- Year: 2008 , Volume: , Series:
- Structural Analysis ; Structure types ; Masonry Structures ; Earthquake engineering
- Keywords: 3D seismic analysis ; non-uniform torsion theory ; Masonry Combined Systems
- Description
- Recent numerical analyses on some types of planar Masonry Combined Systems (MCSs) showed a great
variability of the lateral stiffness along the height, following to the mutual interaction between different parallel structural elements. This may induce significant eccentricities between centre of mass and centre of rigidity, in addition to the ones potentially due to U-shaped walls placed at the perimeter of the building or to irregular in-plan frame-wall dual systems. The mixed structure of the building becomes dramatically prone to damage
due to twist-induced displacements, so a 3D seismic analysis is required to account for its torsional response. In this paper a matrix algorithm for seismic analysis of structural systems formed by masonry or Reinforced Concrete (RC) shear walls (with or without openings), frames and structural cores, is proposed. Such lateral load-resisting elements are considered to be arbitrarily arranged in plan and subjected to a generic pattern of horizontal forces. The torsional stiffness matrix of the cores is built up by means of the non-uniform torsion theory and the stiffness matrix of the whole mixed structure is subsequently defined. The presented analytical formulation provides a good prediction of the seismic behaviour of torsionally
eccentric buildings with MCSs, and allow to evaluate strength and displacement demands.
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- Long term compressive testing of masonry – test procedure and practical experience.
- L. Binda ; L Schueremans ; E. Verstrynge ; S. Ignoul ; D.V. Oliveira ; P.B. Lourenço ; C. Modena
- Book Title / Journal: In D. D’Ayala & E. Fodde (eds.), Structural Analysis of Historic Construction, Taylor & Francis Group, London,
- Year: 2008 , Volume: , Series:
- Structure types ; Masonry Structures
- Description
- The sudden collapses in Italy (Civic Tower of Pavia 1989, Noto Cathedral, 1996) initiated the research into long term behaviour of historical masonry structures. Last decade, international ad hoc collaboration was established within several research inatitutes in Europe. The testing on masonry samples identified the creep behaviour as a possible cause of the collapse of historical masonry buildings. Secondly, research focused on the study of the factors affecting creep (rate of loading, stress level,..) and efforts were made to set up the most suitable testing procedures to understand the phenomenon. The gained insight in the long term behaviour and its description by means of rheological models, is validated mainly by means of long term testing, identifying significant parameters (strain rate of secondary creep phase, damage parameters…).
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- Blended lime-cement mortars for conservation purposes: Microstructure and strength development
- O. Cizer ; K. Van Balen ; D. Van Gemert ; J. Elsen
- Book Title / Journal: In D. D’Ayala & E. Fodde (eds.), Structural Analysis of Historic Construction, Taylor & Francis Group, London,
- Year: 2008 , Volume: , Series:
- Structure types ; Masonry Structures
- Description
- Blended lime-cement mortars are commonly used in conservation practices even though they
may show lack of adequate strength and durability for certain cement-lime compositions. This paper focuses
on understanding the hardening reactions and their influence on the strength development, microstructure and
porosity for the cement-lime mortars in various compositions. Mortars composed of 30%, 50% and 70% cement replacement with lime hydrate and lime putty by mass were studied. Cement hydration has been found to contribute to the early stage strength development while carbonation is mostly favoured after 3 days and contributes
to the strength development until 180 days. The degree of carbonation is much more pronounced with increasing
lime content and porosity of the mortars and the reaction is still in progress at 90 days. All the blended mortars
revealed lower compressive and flexural strength than that of the reference cement mortar due to their lower
cement content and higher porosity. Long-term compressive strength development has been achieved after 180
days while flexural strength for certain mortar compositions does not increase beyond 28 days. Unlike cement
mortar, the mortars blended with lime hydrate and lime putty exhibit an elastic-plastic deformation before failure
occurs, which is preferred for repair mortars to adapt to differential settlements and to allow more deformation
under critical stresses in the masonry.
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- Advances on the Design of Thin Surface Structures in Reinforced Concrete
- K. Palacio
- PhD Thesis, Universidade do Minho
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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- Experimental Investigation of Composite Ultra-High-Performance Fiber-Reinforced Concrete and Conventional Concrete Members
- K. Habel ; E. Denarie
- ACI Structural Journal
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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- Assessment of the material properties of New Zealand's unreinforced masonry building stock
- A.P. Russell ; J.M. Ingham ; H. Mahmood
- Third International Conference on Structural Engineering, Mechanics and Computation, Cape Town, South Africa, A. Zingone (ed.) Structural Engineering, Mechanics and Computation 3, pages 1623-1628.
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Masonry Structures
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- Justification of ACI 446 Code Provisions for Shear Design of Reinforced Concrete Beams
- Z.P. Bazant
- ACI Structural Journal
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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- Multiple Corrosion Protection Systems for Reinforced Concrete Bridge Components
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- Book Title / Journal: Publication No. FHWA-HRT-07-043, U.S. Department of Transportation, Federal Highway Administration, McLean, VA, USA
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
- Description
- Eleven systems combining epoxy-coated reinforcement with another corrosion protection system are evaluated using the rapid macrocell, Southern Exposure, cracked beam, and linear polarization resistance tests. The systems include bars that are pretreated with zinc chromate to improve the adhesion between the epoxy and the reinforcing steel; two epoxies with improved adhesion to the reinforcing steel; one inorganic corrosion inhibitor, calcium nitrite; two organic corrosion inhibitors; an epoxy-coated bar with a primer containing microencapsulated calcium nitrite; the three epoxy-coated bars with improved adhesion combined with the corrosion inhibitor calcium nitrite; and multiple coated bars with an initial 50-μm (2-mil) coating of 98 percent zinc and 2 percent aluminum followed by a conventional epoxy-coating. The systems are compared with conventional uncoated reinforcement and conventional epoxy-coated reinforcement. The results presented in this report represent the findings obtained during the first half of a 5-year study that includes longer-term ASTM G 109 and field tests. In the short-term tests used to date, the epoxy-coatings evaluated provide superior corrosion protection to the reinforcing steel. The results also indicate that the bars will continue to perform well in the longer term, although the tests do not evaluate the effects of long-term reductions in the bond between the epoxy and the reinforcing steel. The corrosion rate on the exposed regions of damaged epoxy-coated reinforcement is somewhat higher than the average corrosion rate on the surface of uncoated reinforcement subjected to similar exposure conditions. The use of concrete with a reduced water-cement ratio improves the corrosion performance of both conventional and epoxy-coated reinforcement in uncracked concrete but has little effect in cracked concrete. Increased adhesion between the epoxy and reinforcing steel provides no significant improvement in the corrosion resistance of epoxy-coated reinforcement. It appears that corrosion inhibitors in concrete and the primer coating containing microencapsulated calcium nitrite improve the corrosion resistance of the epoxy-coated steel in uncracked concrete, but not in cracked concrete. The zinc coating on the multiple coated bars acts as a sacrificial barrier and provides some corrosion protection to the underlying steel in both uncracked and cracked concrete. The degree of protection, however, cannot be evaluated based on the results available to date.
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- Bond Characteristics of High-Strength Lightweight Concrete
- D.W. Mitchell
- ACI Structural Journal
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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- Guide to Concrete for Housing
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- CCAA T53. Cement Concrete & Aggregates Australia
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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- Application Of Laser Shearography For Detecting Microcracks In Concrete
- H. Khong
- MSc Thesis, Department of Civil Engineering, University of Maryland
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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- Characterization of Damage in Mortar and Concrete Specimens due to Delayed Ettringite Formation (DEF)
- J. Ceesay
- PhD Thesis, Department of Civil Engineering, University of Maryland
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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- Seismic Strengthening of Rocking-Critical Masonry Piers
- D.C. Rai ; S. Goel
- Journal of Structural Engineering, ASCE, pp. 1445-1452
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Masonry Structures
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- Evaluation of safety of pointed masonry arches through the Static Theorem of Limit Analysis
- E. De Rosa ; F. Galizia
- ARCH'07: 5th International Conference on Arch Bridges, Multicomp, Lda Publishers, Madeira, pages 659- 668
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Masonry Structures
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