Title:
Thermal Behaviour of High Volumn Fly Ash Concrete and Its Teperature Simulation
Author(s):
Peter G. Gaunt, Mathew K.R. Versfeld, André Ferreira and Stephen O. Ekolu
Publication:
Symposium Paper
Volume:
320
Issue:
Appears on pages(s):
47.1-47.16
Keywords:
compressive strength, ConcreteWorks simulation, durability, heat of hydration, high volume fly ash concrete, temperature
DOI:
10.14359/51701085
Date:
8/1/2017
Abstract:
In this paper, it is shown that Class F fly ash can be effectively used in high volumes as a supplementary cementitious material. High Volume Fly Ash (HVFA) use is of interest in
promoting the development and application of green materials. In South Africa, there is little or no literature on high volume incorporation of locally available fly ash in concrete. In this
investigation, six different concrete mixtures with water/cementitious ratios of 0.3 and 0.45, were used. The mixtures consisted of 0, 30, 50 and 70% fly ash. Tests carried out were workability, compressive strength and heat of hydration. Large 300 mm cubes were used to study hydration heat development in fresh concrete. As expected, concrete strength decreased as fly ash content increased owing to the slower rate of strength development in fly ash mixtures. It was found that heat of hydration generated in HVFA mixtures gave lower peak temperatures compared to mixtures without fly ash, producing reductions of 27% to 43.5% in peak temperatures for mixtures containing 50% and 70% fly ash respectively. Temperature simulation using ConcreteWorks gave predictions correctly depicting the measured temperature profiles but with slight under-estimation of peak temperatures.