Studies of the reactivities and defect structures of cement minerals

Three cement minerals, viz. tricalcium aluminate, monocalcium aluminate, and β-dicalcium silicate have been studied by the technique of thermoluminescence. This method has provided useful information regarding defects in these compounds which act as electron- or hole-traps and which may be implicated in hydration, and other reactions, of such compounds. Trap depths and frequency factors have been calculated by a number of methods and these methods have also been discussed. Trapping of thermoluminescence mechanisms, trap distributions, the effect of thermal treatment, and other data, have also been obtained and studied. In one case an electron trapping defect was tentatively identified. Electron spin resonance spectroscopy has provided valuable complementary information about the environments of defects in these compounds, and trapping/thermoluminescence mechanisms. A trapping defect has been identified in one case, and a donor in another case. Reflectance spectroscopy has given information concerning excitation processes. Auger electron spectroscopy has provided data concerning certain chemical reactions on the surface of tricalcium aluminate. Some thermoluminescence and electron spin resonance data have been obtained for certain other compounds. The thermoluminescence technique has been evaluated in the light of such studies.