Performance of High-Volume Fly Ash Concrete Incorporating Lime Water

The use of concrete containing high-volume fly ash (HVFA) has recently gained popularity as a resource-efficient, durable, and sustainable option for a variety of concrete applications. The long-term creep and drying shrinkage of HVFA concrete containing 65% fly ash (HVFA-65) incorporating lime water has been investigated up to 1 year. Moreover, tensile strength and elastic modulus of HVFA-65 concrete have been examined in conjunction with microstructural development. The HVFA-65 concrete achieved ~200 microstrain of creep at the first 50 days; however, it only obtained approximately 100 microstrain between 50 and 365 days. This is equivalent to one-third of total creep strain displayed by portland-cement (PC) concrete, and also half of the predicted creep strain in accordance with AS 3600. Amalgamation of calcium-alumina-silicate-hydrate (C-A-S-H) gel with calcium-silicate-hydrate (C-S-H) gel was seen to positively affect the compactness and packing density of the gel matrix, which in turn influences the strength and elastic modulus development in HVFA-65 concrete. Early-age curing is also identified as significant in controlling drying shrinkage of the concrete. Keywords: creep; drying shrinkage; fly ash; high-volume fly ash concrete; mechanical properties; microstructure development.