Stress-Strain Relationship of High-Strength Fiber Concrete in Compression

TLDR

The study characterizes the stress‑strain relationship of high‑strength fiber concrete in compression using cylindrical and prismatic specimens. The authors tested concrete strengths of 70–120 MPa with varying steel‑fiber volume fractions and casting orientations, and proposed an analytical model to generate full stress‑strain curves for cylinders and horizontally cast prisms. Fiber inclusion increases strength and peak‑stress strain, though upright specimens show a lower initial tangent modulus; vertically cast prisms exhibit higher peak strains and better post‑peak ductility, and the proposed model aligns well with experimental curves.

Abstract

Tests conducted to characterize the stress-strain relationship of high-strength fiber concrete in compression using both cylindrical and prismatic specimens are reported. The concrete strength investigated ranges from 70 to 120 MPa. Other parameters include volume fraction of steel fibers and direction of casting in relation to the loading axis. Test results indicate that inclusion of fibers improves the strength and enhances the strain at peak stress but results in a smaller initial tangent modulus for specimens cast in an upright (vertical) position. Vertically cast prisms provide higher strains at peak stress and better postpeak ductility than cylindrical specimens. Based on the test data, an analytical model is proposed to generate the complete stress-strain σ-ε curves of high-strength fiber concrete derived from cylinders and horizontally cast prisms. The proposed model has been found to agree well with the stress-strain curves generated experimentally.