Published online by Cambridge University Press: 15 February 2011
Using backscattered electron images, it is shown that an expansive clinker is polymineralic in nature, with individual particles containing the constituents (lime, anhydrite and anhydrous calcium sulphoaluminate) to form ettringite on hydration. The hydration reaction with time of a simple paste of a mixture of this expansive clinker with Ordinary Portland Cement (OPC) has been monitored using backscattered electron images, and the formation of ettringite and a change in the morphology of the calcium hydroxide formed from the added free lime from the expansive clinker is observed. Thermal analysis studies on pastes of the pure expansive clinker have confirmed this apparent change in morphology.