Title: Behavior and Design of HSC Members Subjected to Axial Compression and Flexure

Author(s): H.C. Mertol, S.J. Kim, A. Mirmiran, S. Rizkalla, and P. Zia

Publication: Symposium Paper

Volume: 228

Issue:

Appears on pages(s): 395-420

Keywords: column; combined compression and flexure; compressionmembers; high-strength concrete; stress block parameters

DOI: 10.14359/14483

Date: 6/1/2005

Abstract:
This paper identifies the fundamental design issues related to the behavior of high-strength concrete (HSC) members with compressive strengths up to 124 MPa (18 ksi) subjected to axial compression loads. The findings are based on critical assessment and synthesis of available data, the experiences of bridge owners, concrete fabricators, and current bridge design codes from North America, Europe, Australia, and Asia. The paper discusses the various factors believed to affect the design and behavior of HSC compression members, including the fundamental properties of concrete, member geometry, support conditions, main and lateral reinforcement, and type of construction. The significance of modeling of the stress-block, potential early spalling of concrete and reliability issues of HSC columns is also discussed. This paper represents the current efforts by the authors to recommend revisions to the AASHTO-LRFD Bridge Design Specifications, which currently limits the compressive strength of concrete to 69 MPa (10 ksi).