Revisiting the Effect of Slag in Reducing Heat of Hydration in Concrete in Comparison to Other Supplementary Cementitious Materials
Loading...
Date
2018-09-27
Authors
Moon, Hoon
Ramanathan, Sivakumar
Suraneni, Prannoy
Shon, Chang-Seon
Lee, Chang-Joon
Chung, Chul-Woo
Journal Title
Journal ISSN
Volume Title
Publisher
MDPI
Abstract
Blast furnace slag (SL) is an amorphous calcium aluminosilicate material that exhibits
both pozzolanic and latent hydraulic activities. It has been successfully used to reduce the heat of
hydration in mass concrete. However, SL currently available in the market generally experiences
pre-treatment to increase its reactivity to be closer to that of portland cement. Therefore, using such
pre-treated SL may not be applicable for reducing the heat of hydration in mass concrete. In this
work, the adiabatic and semi-adiabatic temperature rise of concretes with 20% and 40% SL (mass
replacement of cement) containing calcium sulfate were investigated. Isothermal calorimetry and
thermal analysis (TGA) were used to study the hydration kinetics of cement paste at 23 and 50 ◦C.
Results were compared with those with control cement and 20% replacements of silica fume, fly
ash, and metakaolin. Results obtained from adiabatic calorimetry and isothermal calorimetry testing
showed that the concrete with SL had somewhat higher maximum temperature rise and heat release
compared to other materials, regardless of SL replacement levels. However, there was a delay in
time to reach maximum temperature with increasing SL replacement level. At 50 ◦C, a significant
acceleration was observed for SL, which is more likely related to the pozzolanic reaction than the
hydraulic reaction. Semi-adiabatic calorimetry did not show a greater temperature rise for the
SL compared to other materials; the differences in results between semi-adiabatic and adiabatic
calorimetry are important and should be noted. Based on these results, it is concluded that the use of
blast furnace slag should be carefully considered if used for mass concrete applications.
Description
Keywords
blast furnace slag, calcium sulfate, heat of hydration, maximum temperature rise, adiabatic calorimeter, semi-adiabatic calorimeter, isothermal calorimeter
Citation
Moon, H.; Ramanathan, S.; Suraneni, P.; Shon, C.-S.; Lee, C.-J.; Chung, C.-W. Revisiting the Effect of Slag in Reducing Heat of Hydration in Concrete in Comparison to Other Supplementary Cementitious Materials. Materials 2018, 11, 1847.