Title: Effect of Slag Characteristics on Adiabatic Temperature Rise of Blended Concrete

Author(s): Hai Zhu, Dhanushika Gunatilake Mapa, Catherine Lucero, Kyle A. Riding, and A. Zayed

Publication: Materials Journal

Volume: 119

Issue: 1

Appears on pages(s): 117-131

Keywords: adiabatic temperature rise; heat of hydration; limestone cement; ordinary portland cement; slag alumina content; slag characteristics; slag magnesia content

DOI: 10.14359/51733150

Date: 1/1/2022

Abstract:
Incorporation of slag generally reduces the heat of hydration and temperature rise of concrete mixtures, but the heat generation in slag-blended mixtures may also be affected by the physical and chemical characteristics of slag. In this paper, the temperature rise was studied in multiple cement-slag combinations, with a focus on slag characteristics. Varying alumina contents of slags from 8 to 17% indicated a substantial difference in the adiabatic temperature rise. Lower magnesia content increased the initial reactivity of the slag, leading to a higher rate of temperature rise during the first 24 hours. The alumina content and magnesia-to-alumina ratio of slags were found to affect temperature evolution in the concrete mixtures. A sensitivity analysis showed that the inclusion of 60% slag could reduce the temperature rise and gradients within the concrete element compared to the control mixtures. However, this reduction in temperature diminished as the member size increased and was also affected by the slag and cement composition. The study also developed new concrete adiabatic temperature rise curves for control mixtures of Type II (moderate heat) and Type IL cements and their corresponding slag-blended mixtures. The curves were developed for placement temperatures ranging from 40 to 100°F (4.4 to 38°C). This data will supplement the current specifications and the design of thermal control plans for massive concrete elements.