CFB炉渣代机制砂对混凝土强度的影响机理

Influence Mechanism of Circulating Fluidized Bed Slag Replacing Machine-Made Sand on Concrete Strength

摘要:

研究了循环流化床（CFB）炉渣代机制砂对混凝土强度的影响机理，测试了不同CFB炉渣代砂率混凝土的强度，通过模拟试验分析了CFB炉渣和煤气化渣在混凝土环境中的强化机理，测试了CFB炉渣与煤气化渣的水化活性，并观测了CFB炉渣、机制砂和煤气化渣胶砂界面的微观形貌.结果表明：随着CFB炉渣代砂率的提高，混凝土用水量升高，7 d抗压强度降低，28 d抗压强度先升高后降低，且7~28 d抗压强度增长率大幅提升；CFB炉渣可以吸收水泥浆体而强化自身，同时其高活性可以强化混凝土的界面结构；CFB炉渣储存的水具有内养生作用，可以提高周围水泥的水化程度.

Abstract:

Influence mechanism of circulating fluidized bed （CFB） slag replacing machine-made sand on concrete strength was studied. The strength of concrete with different replacement rate of CFB slag was tested. The strengthening mechanism of CFB slag and coal gasification slag in concrete environment was analyzed by simulation tests. The hydration activity of CFB slag and coal gasification slag was tested. The interface micromorphology of CFB slag， machine-made slag and coal gasification slag was observed. The results show that with the increase of replacement rate of CFB slag， the water consumption of concrete increases， the compressive strength at 7 days decreases， the compressive strength at 28 days first increases and then decreases， and the growth rate of compressive strength from 7 days to 28 days increases significantly. CFB slag can absorb cement slurry to strength itself， and its high activity can strengthen the interface structure of concrete. The water stored in CFB slag has the function internal curing and can improve the hydration of the surrounding cement.