Title: Stress-Strain Model for Various Unconfined Concretes in Compression

Author(s): Keun-Hyeok Yang, Ju-Hyun Mun, Myung-Sug Cho, and Thomas H.-K. Kang

Publication: Structural Journal

Volume: 111

Issue: 4

Appears on pages(s): 819-826

Keywords: compressive strength; density; modulus of elasticity; stressstrain model

DOI: 10.14359/51686631

Date: 7/1/2014

Abstract:
This study aims to develop a simple and rational stress-strain model that is applicable to unconfined concretes in compression, covering a wide range of compressive strengths between 10 and 180 MPa (1.5 and 26.1 ksi) and concrete densities between 1200 and 4500 kg/m3 (75 and 280 lb/ft3). In developing the stressstrain model, the modulus of elasticity, the strain at peak stress, and the strain at 50% of the peak stress on the descending branch were formulated using regression analysis of 3295, 415, and 96 data points, respectively. Numerical and statistical analyses were then performed to derive equations for the key parameter determining the shapes of the ascending and descending branches of the stress-strain curves. The reliability of the developed model was confirmed by comparisons with actual stress-strain curves obtained from 100 specimens with different compressive strengths and densities. On the other hand, other existing models were shown to have limitations for use on lightweight concrete, heavyweight concrete, and high-strength concrete.