[Geotechnical Engineering]

Luo, W., Jin, X. G., Zhang, Z. Y. Triaxial test on concrete material containing accelerators under physical sulphate attack[J]. Construction & Building Materials, 2019, 206: 641-654.

Keywords: Accelerating concrete material; Physical sulphate attack; Chemical sulphate attack; Triaxial compression; Mechanical property

Abstract:

Triaxial tests were conducted to study the impact of a physical sulphate attack (PSA) on the mechanical properties of concrete containing accelerators. Concrete samples were prepared using field materials while strictly complying with Chinese standards. A total of 94 accelerating concrete cylinder samples (a 50 mm 100 mm) were tested. The samples were separated into four groups according to the concentrations of the sulphate solution and the immersion time. The triaxial test results show that the samples under a low concentration of sulphate exhibit the characteristics of a chemical sulphate attack on the failure model, stress–strain curve, and strength properties, whereas the samples subjected to a high concentration of sulphate generate unique characteristics of a physical sulphate attack. The samples under a PSA display different mechanical properties compared with those under a chemical sulphate attack, particularly within respect to the static elastic modulus and compressive strength. A PSA leads to an evolution of the static elastic modulus of the accelerating concrete samples with a proportionally decreasing trend. This trend can be explained by the crack damage stress threshold of the volume strain model. The Mohr–Coulomb failure criterion is used to calibrate the test results of the mechanical properties of the accelerating concrete samples exposed to different concentrations of a sulphate solution. The cohesion in the Mohr–Coulomb criterion exhibits a relationship with the number of d of exposure and the concentration of the Na2SO4 solution.