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Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The use of high-strength concrete (HSC), with strengths reaching 130 MPa, has increased in recent years due to its superior performance and strength. Structures are designed and built using HSC, especially in columns of multistory buildings. The rectangular stress block specified in the ACI 318-02 Building Code for design of reinforced concrete elements was developed, however, on the basis of normal-strength concrete column tests. The applicability of the ACI rectangular stress block to higher-strength concretes becomes questionable, especially for members under high levels of axial compression. A new rectangular stress block is introduced in this paper for a wide range of concrete strengths between 20 and 130 MPa. The proposed stress block is verified against available test data. Column strengths computed using the stress block show good agreement with those recorded experimentally. [ABSTRACT FROM AUTHOR]

Lateral prestressing of concrete columns was investigated as a method of seismic retrofit. Experimental research was conducted to develop a design procedure for shear deficient concrete columns. The technology consists of external prestressing of columns in transverse direction by means of individual hoops that consist of prestressing strands and specially designed anchors. Seven full-scale columns were tested under constant axial compression and incrementally increasing lateral deformation reversals. The results, presented and discussed in this paper, indicate that the retrofit methodology can suppress shear failure, promote flexural behavior, and increase inelastic column deformability substantially. A design procedure is presented for seismic retrofit of shear-deficient columns to achieve two different levels of performance. [ABSTRACT FROM AUTHOR]

Presents information on a study which developed a mathematical model to express the stress-strain relationship of high strength concrete confined by transverse reinforcement. Details on the proposed model; Results and discussion; Summary and conclusion.

Presents information on a study which investigated the behavior of high-strength concrete columns under different levels of axial compression. Experimental Program; Results; Conclusion.

This paper provides a summary of the damage to bridges in the Mw 8.8 Chile earthquake of 27 February 2010. Lessons from the different types of structural damage observed on concrete and steel bridges are discussed. The important roles played by soil liquefaction, settlement and embankment failures are highlighted. Aspects such as shear failure of steel piles, shear failure of concrete substructure elements, failures and severe buckling of steel braces, failures of shear keys and restrainers at supports, and damage to girders due to lack of diaphragms are described. Many examples of loss of superstructure support are presented. Skew supports and multi-span simply supported bridges were particularly susceptible to loss of support. Several aspects of the Chilean bridge design code are discussed and compared with North American codes (CSA S6 and AASHTO). [ABSTRACT FROM AUTHOR]