Department of Civil Engineering, University of Pretoria, Pretoria, South Africa
Shekhovtsova, J., Department of Civil Engineering, University of Pretoria, Pretoria, South Africa; Kovtun, M., Department of Civil Engineering, University of Pretoria, Pretoria, South Africa; Kearsley, E.P., Department of Civil Engineering, University of Pretoria, Pretoria, South Africa
Short- and long-term properties of alkali-activated fly ash concrete, namely, compressive, flexural and splitting tensile strengths, modulus of elasticity, Poisson ratio, early-age and drying shrinkage, creep and durability performance have been investigated in this paper. Blended ordinary Portland cement-fly ash concrete was used as a reference. The average compressive and flexural strengths of alkali-activated fly ash concrete at 28 d were 45 MPa and 5.8 MPa, respectively; drying shrinkage and creep values were about 360 and 200 microstrain, respectively, at 1 year. The total early-age shrinkage during the first 24 h of curing was lower for alkali-activated fly ash concrete at 1460 microstrain compared to 2800 microstrain for blended cement concrete. The use of this non-Portland cement containing material for producing precast concrete units can utilise high volumes of fly ash and potentially reduce the carbon footprint of the final product.
Carbon; Carbon footprint; Concretes; Creep; Curing; Drying; Fly ash; Portland cement; Precast concrete; Shrinkage; Tensile strength; Alkali-activated fly ashes; Compressive and flexural strengths; Durability performance; Early age shrinkages; Fly ash concretes; Long-term properties; Ordinary Portland cement; Splitting tensile strength; Cements