High-Strength Concrete in Uniaxial Tension

Abstract

The behavior of high-strength concrete (HSC) subjected to uniaxial tension was investigated in this paper. The complete tensile stress-deformation response of HSC was acquired through an extensive experimental program. The experimental program comprised of testing concrete with compressive strengths equal to 6 ksi (41 MPa), 12 ksi (83 MPa), and 15 ksi (103 MPa). An analytical expression was proposed for the relationship between the axial stress and crack width in HSC. This relationship was developed for the determination of fracture parameters such as fracture energy and the characteristic length for the three compressive strengths. The higher compressive strength concretes exhibited larger fracture energies and lower characteristic lengths. A relationship between the tensile and compressive strengths of HSC was established. Although HSCs exhibit larger tensile strengths, there is a decrease in the ratio of tensile-to-compressive strength at higher compressive strengths. Accordingly, the uniaxial tensile strength of HSC can be predicted by the expression f't = 6.1 times the square root of f'c, where f't and f'c are the tensile and compressive strengths, respectively. In comparison with the expression developed for normal strength concrete (f't = 6.5 times the square root of f'c), this expression predicts lower tensile strengths at higher strength levels.