Title: Performance of High-Volume Fly Ash Concrete Incorporating Lime Water

Author(s): C. Gunasekera, X. H. Ling, S. Setunge, D. W. Law, and I. Patnaikuni

Publication: Materials Journal

Volume: 115

Issue: 2

Appears on pages(s): 289-297

Keywords: creep; drying shrinkage; fly ash; high-volume fly ash concrete; mechanical properties; microstructure development

DOI: 10.14359/51701238

Date: 3/1/2018

Abstract:
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 longterm 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 calciumalumina-silicate-hydrate (C-A-S-H) gel with calcium-silicatehydrate (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.