铝污泥灰改性混凝土水化及耐硫酸腐蚀特性

为探究铝污泥灰改性混凝土水化特性，对煅烧后铝污泥灰按照不同掺量(0%、10%、20%、30%)制备试样并进行XRD、TG、SEM测试，结合耐硫酸腐蚀实验分析其抗腐蚀特性。结果表明：铝污泥灰掺量为10%~20%时，可以提高混凝土的抗折抗压强度，抗硫酸侵蚀性能在掺量为20%时最优。这是由于铝污泥灰的火山灰效应产生水化硅酸钙凝胶 (C-S-H) 充填毛细孔隙所致，微集料效应还可细化混凝土孔隙，提高混凝土微观结构致密化水平；另一方面，铝污泥灰的掺入，降低体系的Ca/Si比，提高Al/Si比，减少了水化产物Ca(OH)₂含量，促进C-A-H等耐酸侵蚀物相的生成，从而降低了侵蚀介质的侵入与腐蚀速度。本研究可为混凝土改性及耐蚀混凝土研发提供参考。

Hydration and sulfuric acid corrosion resistance of aluminum sludge ash modified concrete

In order to investigate the hydration characteristics of water supply aluminum sludge ash modified concrete, samples were prepared with different dosages (0%, 10%, 20%, 30%) of calcined water supply aluminum sludge ash and subjected to XRD, TG, SEM tests. Combined with sulfuric acid corrosion resistance experiments, their corrosion resistance characteristics were analyzed. The results show that when the amount of aluminum sludge ash added to the water supply is 10%~20%, the flexural and compressive strength of concrete can be improved, and the sulfuric acid corrosion resistance performance is optimal at the amount of 20%. This is due to the pozzolanic effect of water supply aluminum sludge ash, which produces hydrated calcium silicate gel (C-S-H) to fill capillary pores. The micro aggregate effect can also refine concrete pores and improve the densification level of concrete microstructure; On the other hand, the addition of aluminum sludge ash in water supply reduces the Ca/Si ratio of the system, increases the Al/Si ratio, reduces the content of hydration product Ca(OH)2, promotes the formation of acid resistant phases such as C-A-H, and thus reduces the invasion and corrosion rate of the corrosive medium.This study can provide reference for concrete modification and the development of corrosion-resistant concrete.