Title: Heat Contribution of Slag to Temperature Development of Mass Concrete
Author(s): Rodrigo Antunes
Publication: Materials Journal
Appears on pages(s): 115-126
Keywords: aluminum oxide (Al2O3); Blaine fineness; concrete mixtures; slag; sulfur trioxide (SO3); temperature rise; tricalcium aluminate (C3A)
The novel approach employed in this study identified the heat contribution of slag to the temperature development of concrete with different types of cement. A total of 126 field temperature measurements were analyzed, along with aluminum oxide (Al2O3) and Blaine fineness (BF) of portland cement and slag cement. After the dormancy period, stage three of the cement hydration process initiated 4 to 6 hours before for mixtures with 60% slag cement. Variations in the Al2O3 content in concrete mixtures as low as 1% appear to have a negligible effect on the thermal development of concrete. Conversely, a 0.8% lower sulfur trioxide (SO3) content in concrete can increase the tricalcium aluminate (C3A) concentration at early ages and accelerate heat generation. Type IL cement appears to be suitable for most mass concrete applications because the additional BF provided negligible additional heat generation. The energy (E) generated in the massive elements investigated yielded a strong correlation with the volume (V) of the elements. However, the temperature rise (TR) of the concrete presented a weak correlation to the concrete temperature at placement (TC), contradicting the current standards.