Portland cement and derived blended cements, represent binding matrices adequate for the immobilization of hazardous waste. The high pH of the intergranular pore solution in the cement stone along with the presence of calcium silicates hydrates with high specific surface area, as main hydrates, are key elements in the immobilization capacity of noxious elements in these matrices. Portland clinker free binding systems such as alkali activated slag have also a good immobilization capacity of toxic elements such as heavy metals.

The present study brings information regarding the immobilization of a glass waste with high Pb content (> 15%), derived from cathode ray tube glass (CRT) recycling, in three types of matrices: ordinary Portland cement (CEM I), slag cement (CEM III A) and alkali – activated slag binder. All binders showed a good immobilization capacity of the Pb waste (over 99%).

The mechanical strengths developed by the ordinary Portland cement were not adversely affected by the presence of CRT waste (dosed in amounts corresponding to 0.18-10% Pb content).

The compressive strength recorded for the slag cement with a high amount of waste (corresponding to 10% Pb) decreased with 25% and for alkali activated slag with 15% (with reference to the binder without waste).