Heat evolution in composite cements with additions of Sn(II) and Sn(IV) chlorides

The heat evolution in three high-replacement composite cement pastes—that is, Portland cement mixed with 75% and 90% ground granulated blast furnace slag and 75% pulverised fuel ash, alongside a 100% ordinary Portland cement, has been followed using isothermal conduction calorimetry at 35°C. The effects of adding 0·1% and 1% SnCl₂.2H₂O and SnCl₄.5H₂O on their heat outputs have also been studied. Results indicate that there is a significant difference between the Portland cement and the three composite cements in terms of their heat output. The addition of tin chlorides also causes complex changes to the setting times and heat output of the various cements.