Geopolymer have gradually become an alternative materials for hazardous and radioactive waste immobilization. However, the compatibility between radioactive waste and geopolymer in various extreme conditions are still not clear. In this study, the thermal stability of geopolymer solidified product of Sr contaminated zeolite A was investigated. For this purpose, the specimens after standard curing were subjected to temperatures of 600, 700 and 800 degrees C for 2h. Freeze-thaw cycles were also employed to test the thermal stability of geopolymer matrices. Meanwhile, changes in the leaching characteristics and physical properties were analyzed. Analysis showed that geopolymer - Sr contaminated zeolite A blends exhibited excellent thermal stability. Although elevated temperature and freeze-thaw cycles led to the deterioration of geopolymer matrices, the leaching rate and mechanical properties of solidified product were still acceptable. The resluts obtained indicated that geopolymer appeared to be very suitable for radioactive waste immobilization.
(Radioactive waste immobilization)
