Title: Reinforced High-Strength Concrete Beams in Flexure

Author(s): M. A. Rashid and M. A. Mansur

Publication: Structural Journal

Volume: 102

Issue: 3

Appears on pages(s): 462-471

Keywords: beam; crack; deflection; ductility; flexural strength; high-strength concrete; reinforced concrete

DOI: 10.14359/14418

Date: 5/1/2005

Abstract:
Flexural test results generated on 16 reinforced concrete beams to evaluate the implications of using high-strength concrete (HSC) are reported. Test parameters considered include concrete compressive strength, ratios of tensile and compressive reinforcements, and spacing of lateral ties. It is found that the current code provisions for serviceability requirements of maximum crack width and ultimate strength are adequate up to a concrete strength of approximately 130 MPa. Concerns, however, are expressed regarding the adequacy of those for cracking moment and service load deflection. It is shown that stresses generated by shrinkage of concrete and the creep associated with it can significantly affect the cracking moment and service load deflection of reinforced HSC beams. Also, some detailing requirements for compression reinforcement need to be reassessed so as to utilize its full strength potential and ensure adequate ductile response of the beam when HSC is involved.