关键词: 超细粉煤灰;CFB炉渣;免烧砖;抗冻性

Abstract: The effect of ultrafine fly ash on freeze resistance of CFB slagbaking -free bricks was studied by means of apparent density, compressive strength, water absorption and mass loss rate after freeze -thawed. The influence and mechanism of ultra -fine ash content on compressive strength andfreeze resistance of the materials was investigated.The apparent density and compressive strength increase first and then decrease with the increase of the amount of ultra -fine fly ash.When ultra-fine fly ash content is 5％, the compressive strength of CFB slag baking -free bricks reaches the maximum value (134.6 MPa).After 15 freeze-thaw cycles, the mass loss rate of CFB slagbaking-free bricks decreased with the increase of the content of ultra-fine fly ash and reached the lowest when the content of ultra -fine fly ash was 5％.

Key words: ultra-fine ash;CFB slag;baking-free brick;freeze resistance