复合活化沸石粉对水泥胶砂性能影响研究

沸石粉活性较低，在混凝土中掺量较多时，难以成型，使材料强度下降，再加上其比表面积大、吸水率高，导致材料流动度显著降低，不利于实际工程中的应用。为了提升天然沸石粉的活性，使用Ca(OH)₂活化和水热活化复合的方法对沸石粉进行活化处理，等质量取代30%水泥制作胶砂试件，测定其3个龄期的力学强度和流动度，并采用比表面积测定、扫描电子显微镜、X射线衍射、热重试验进行微观机理分析。结果表明：Ca(OH)₂掺量为8%时，胶砂力学强度最高，28 d抗压强度达到35.0 MPa,比掺天然沸石粉的水泥胶砂的抗压强度增加了20.7%;天然沸石粉经复合活化后活性明显提升，最佳Ca(OH)₂掺量为8%,28 d强度活性指数增加16%;复合活化改变了沸石粉表面结构，其表面从粗糙不平变得光滑，有利于流动性增加，且随着Ca(OH)₂掺量的增加，水泥胶砂流动度呈现增长趋势。

Study on Influence of Composite Activated Zeolite Powder on Properties of Cement Mortar

The low reactivity of zeolite powder in concrete, when added in large amounts, hinders molding and reduces material strength. Additionally, its large specific surface area and high water absorption rate significantly decrease material fluidity, which is not conducive to practical engineering applications. To enhance the reactivity of natural zeolite powder, a method combining Ca(OH)₂ activation and hydrothermal activation was used to treat zeolite powder. Sand-cement specimens were made by replacing 30% of the cement with equal mass of activated zeolite powder, and their mechanical strength and fluidity at three different ages were measured. The micro-mechanism was analyzed using specific surface area measurement, scanning electron microscopy, X-ray diffraction, and thermogravimetric analysis. The results showed that the highest mechanical strength of the mortar was achieved when the Ca(OH)₂ content was 8%, with a 28-day compressive strength reaching 35.0 MPa, which is a 20.7% increase compared to the compressive strength of the mortar with natural zeolite powder. The activity of natural zeolite powder was significantly enhanced after composite activation, with the optimal Ca(OH)₂ content being 8%, resulting in a 16% increase in the 28-day strength activity index. The composite activation changed the surface structure of the zeolite powder, making it smoother and more conducive to increased fluidity. Furthermore, as the Ca(OH)₂ content increased, the fluidity of the cement mortar showed an upward trend.