Thermal stability of hydraulic non-cement binder prepared from FBC ash

Abstract

The thermal stability of a non-cement sulfocalcic binder (SCB) prepared from FBC ash was studied at 80 °C, 200 °C and 600 °C for 90 days and compared with the thermal stability of OPC. All the test bodies produced from SCB pastes had been pretreated in a humidity chamber for 28 days. The SCB was found to be stable in terms of strength at temperatures of up to 80 °C. At a temperature of 200 °C, ettringite in the SCB disintegrated and its strength dropped by about 27 % in the initial hours of the experiment, after which the strength of the SCB became stable. At a temperature of 600 °C, the strength of the SCB was seen to drop again by about 46 %. However, in the long term, the SCB at 600 °C appeared more stable when compared to OPC, which can be attributed to the presence of C-A-S-H phase.