Mechanical performances of weathered coal fly ash based geopolymer bricks

In this paper weathered coal fly ash has been used in polycondensation processes aimed at the production of geopolymer–based low temperature ceramic bricks. The ash has been employed both “as received” and after drying, showing favorable reactivity in any case. Different curing conditions with a variable period at 60 °C have been tested. Samples obtained have been characterized by measuring Unconfined Compressive Strength (UCS) and by SEM observations. Good strength values have been obtained with the systems tested. Furthermore, it has been found that mechanical performance increases as the time during which samples are kept at 60 °C increases.