- Ductility of reinforced concrete masonry shear walls under seismic loading
- M. Shedid ; R. Drysdale ; W. El-Dakhakhni
- Book Title / Journal: 14th World Conference on Earthquake Engineering, Beijing, China, Paper 14-05-04-0013
- Year: 2008 , Volume: , Series:
- Earthquake engineering
- Description
- The possibility of achieving a high level of ductility by flexural yielding in fully grouted reinforced concrete
masonry shear walls is evaluated. Six full-scale walls were tested to failure under reversed cyclic lateral loading
to investigate the effects of the amount and the distribution of vertical reinforcement and the level of axial
compressive stress on the inelastic behavior and ductility of reinforced masonry shear walls. The test results
indicated that the top wall displacement at the onset of yielding of the vertical reinforcement was highly
dependent on the amount of reinforcement and minimally affected by the level of axial compressive load.
However, at maximum lateral loads, the wall displacements were less sensitive to the amount of vertical
reinforcement and to the level of axial compression. Correspondingly, the displacement ductility was found to
be very sensitive to the amount of vertical reinforcement compared to the level of axial compression. In general,
high levels of ductility accompanied by relatively small strength degradation were observed for the test
specimens.
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- Seismic response of linear, flanged, and confined masonry shear walls
- M. Shedid ; W. El-Dakhakhni ; R. Drysdale
- Book Title / Journal: 14th World Conference on Earthquake Engineering, Beijing, China, Paper 14-05-04-0015
- Year: 2008 , Volume: , Series:
- Earthquake engineering
- Description
- A potentially limiting feature of reinforced masonry shear walls is the presence of a single line of vertical
reinforcement along the wall length that cannot be effectively tied to delay buckling. Especially under cyclic
loading, when opening and closure of wide cracks occurs, compression closure of the previous tension cracks
causes all of the compressive stresses to be carried by isolated bars at the crack location. This situation affects
the stability of the compression zone and may lead to out-of-plane buckling of the wall or local buckling of the
reinforcement, which can lead to an accelerated degradation in strength due to increased damage. This limitation
may be avoided by using boundary elements at the end zones of the walls or by structurally connecting a linear
wall to an intersecting wall which would limit the damage at the end zone of the wall, provide out-of-plane
stability for the end of the wall, and delay buckling of the vertical bars. The experimental data presented is the
first phase of an investigation of the response of flexural concrete masonry shear walls with various geometries
at the ends of the walls. The conditions studied are the effects of structurally connecting a flange to a linear
reinforced masonry shear wall and of creating a boundary element at each end of the wall. The walls were tested
under reversed lateral cyclic displacement simulating earthquake excitation. Details of the linear, flanged, and
confined wall tests are presented in this paper. In general, high levels of ductility accompanied by relatively
small strength degradation were observed for the test specimens with significant increase in ductility for the
flanged and confined walls.
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- I-35W Mississippi River Bridge Failure - Is it a wake up call?
- N. Subramanian
Paper hosted with permission of the Indian Concrete Journal (ICJ). The paper was first published in the February 2008 issue of The Indian Concrete Journal - Year: 2008
- Bridge management ; Bridges
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- Experimental Investigation of Multihazard Resistant Bridge Piers having Concrete-Filled Steel Tube under Blast Loading
- S. Fujikura ; D. Lopez-Garcia
- Journal of Bridge Engineering, Vol.13, No.6, pp. 586-594. ASCE)
- Book Title / Journal:
- Year: 2008 , Volume: , Series:
- Bridge management ; Bridges
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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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- Multi-criteria approaches for regional earthquake retrofit strategies
- S. Giovinazzi ; S. Pampanin
- 8th Pacific Conference on Earthquake Engineering (8PCEE), Singapore
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Repair and Retrofit of 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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- Mitigation analyses for the selection of effective seismic retrofit strategies at a territorial scale
- S. Giovinazzi ; S. Pampanin
- New Zealand Society of Earthquake Engineering 2007 Conference (NZSEE 2007), Palmerston North, New Zealand, paper 51.
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Repair and Retrofit of Structures
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- An investigation of strengthening of historical masonry constructions by steel skeleton
- B. Kucukdogan
- M.Sc Thesis, the Graduate School of Natural and Applied Sciences of Middle East Technical University
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Repair and Retrofit of Structures
- Keywords: Masonry 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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- Creating fragility functions for performance-based earthquake engineering
- K.A. Porter ; R.E. Bachman ; R. Kennedy
- Earthquake Spectra, Vol. 23, No. 2, pages 471-489
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Earthquake engineering
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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
-
- 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
-
- CCAA T53. Cement Concrete & Aggregates Australia
- Book Title / Journal:
- Year: 2007 , Volume: , Series:
- Structure types ; Concrete structures
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