Dissolution experiments of amorphous alkaline earth silicate (AES) fibres heat-treated in the temperature range 110-1260 deg C have been carried out in a glycine, a simple amino acid, solution. Results of the experiments suggest that variations in the dissolution rate of AES fibres in the glycine solution as a function of heat treatment temperature can be categorised into two types, one of which shoes a peak around 700 deg C, whereas the other exhibits a sharp rise up to 800 deg C and then is kept constant in the temperature range over 800 deg C or over. Meanwhile, the AES fibres of the second category are in the Ca-rich systems and are crystallised dominantly into wollastonite or pseudowollastonite by heating at a temperature of 800 deg C or over.
