A comparative study of the mechanical properties, fracture behavior, creep, and shrinkage of high-volume fly ash concrete

Abstract

The production of Portland cement – the key ingredient in concrete – generates a significant amount of carbon dioxide. However, due to its incredible versatility, availability, and relatively low cost, concrete is the most consumed manmade material on the planet. One method of reducing concrete’s contribution to greenhouse gas emissions is the use of fly ash to replace a significant amount of the cement. This study presents the results of an experimental investigation that compares the mechanical properties, fracture behavior, creep, and shrinkage of high-volume fly ash concrete (HVFAC) – concrete with at least 50% of the cement replaced with fly ash – with conventional concrete (CC). The results show that the CC mix gains compressive strength more rapidly compared with the HVFAC mix. However, differences in compressive strength between both mixes decrease significantly with age. Also, the CC mix has higher creep and shrinkage compared with the HVFAC mix. Statistical data analyses (both parametric and non-parametric) were performed to evaluate whether or not there is any statistically significant difference between the mechanical properties and fracture energy of the HVFAC and CC mix. Results of these statistical tests show that the HVFAC mix has the identical tensile splitting strength with the CC mix, while the HVFAC mix had lower flexural strength and higher fracture energy compared with the CC mix.

Keywords:

• conventional concrete
• creep
• fracture energy
• high-volume fly ash concrete
• mechanical properties
• shrinkage

Acknowledgments

The authors gratefully acknowledge the financial support provided by the Missouri Department of Transportation (MoDOT) and the National University Transportation Center at Missouri University of Science and Technology. The authors would also like to thank the support staff in the Department of Civil, Architectural and Environmental Engineering and Center for Infrastructure Engineering Studies at Missouri S&T for their efforts. The conclusions and opinions expressed in this paper are those of the authors and do not necessarily reflect the official views or policies of the funding institutions.