Effect of fineness and calcium content of fly ash on the mechanical properties of Engineered Cementitious Composites (ECC)

As a new green material, ECC has received extensive attention all over the world because of its potent ability of crack width controlling, excellent behavior of flexural toughness, and fatigue durability. The use of high volume fly ash as a partial replacement of cement reduces environmental pollution and conserves natural resources. This paper presents the experimental results to find out the effect of fineness and calcium content of fly ash on the mechanical properties of ECC. Four different types of fly ash were used and a series of mechanical tests, including cube compressive strength, uniaxial direct tensile, three-point bending and single-crack tension tensile were conducted in this paper. The results indicate that between tensile strain properties and fly ash fineness, there is not just a simply linear relationship. Fineness is not the determining factor for ECC's compression performance, but the activity of fly ash. Fly ash with the higher calcium content did not make the tensile properties of ECCs greater at all ages, but make compressive performance better. (C) 2019 Elsevier Ltd. All rights reserved.