Effect of fire on the deterioration of portland and blended cements

الملخص EN

The effect of thermally treated temperature on ternary blended cement pastes containing ground blast furnace slag (WCS) and ground clay bricks (GCB) was studied.

After moulding, the cement pastes were cured under tap-water for 28 days and dried at 105oC for 24 hours.

The cubes were subjected to heat treatment at rate of 10oC / min and then kept for 3 hours at heating the peak exposure temperature to establish a stable temperature at 200, 300, 400, 500, 600 and 800 oC, then cooled to room temperature in the furnace.

The specimens were covered with plastic film and kept into desiccators in order to avoid the influence of humidity and the carbonization of thermally treated pastes.

The weight loss of blended cement pastes is higher than OPC up to 400oC.

As the heat treatment increases up to 500- 800 oC, the weight loss of OPC increases.

The compressive strength of blended cement pastes increase up to 400 oC, then decreases.

The OPC pastes are deteriorated after 600 oC.

The micrograph of thermally treated blended cement pastes shows dense closed microstructure, displayed the absence of microcracks.