Alternating ultrahigh temperature (AUHT) method for curing cement paste was established to investigate the effects of dry and steam conditions on the compressive strength of the cement paste. X-ray diffraction, thermogravimetry, scanning electron microscopy, and nitrogen adsorption were used to test the phases, chemical structure, microstructure, and pore structure of the cement paste in order to elucidate the mechanisms by which the curing conditions influenced the compressive strength of the cement paste cured at AUHT. The results showed that, when the curing time reached nine days under AUHT-dry conditions, the compressive strength of the cement paste decreased rapidly and continuously. However, when the cement paste was cured under AUHT-steam conditions, its compressive strength was highly stable. When the curing time increased to 21 days, the compressive strength of the cement paste under AUHT-dry conditions decreased to 25.8 MPa, which is only 89% of the compressive strength of the cement paste cured under AUHT-steam conditions. According to the chemical structure, microstructure, and pore structure results, under AUHT-dry conditions, xonotlite formed in the cement paste and its microstructure changed from “network” and “bulk” to “highly-porous spongy-type assembly”, which increased the porosity of the cement paste and reduced its compressive strength. Under AUHT-steam conditions, some new products formed, increasing the total content of hydration products and maintaining their “bulk” microstructure. Therefore, the porosity of the cement paste cured under AUHT-steam conditions was lower than that of the cement paste cured under AUHT-dry conditions, but the compressive strength was higher.

为了研究干燥和蒸汽条件对水泥浆抗压强度的影响，建立了交替超高温固化水泥浆的方法。X射线衍射，热重分析，扫描电子显微镜和氮吸附被用来测试水泥浆的相，化学结构，微结构和孔结构，以阐明固化条件影响水泥浆抗压强度的机理。水泥浆在AUHT固化。结果表明，在AUHT干燥条件下固化时间达到9天时，水泥浆的抗压强度迅速连续下降。但是，当水泥浆在AUHT蒸汽条件下固化时，其抗压强度非常稳定。当固化时间增加到21天时，在AUHT干燥条件下水泥浆的抗压强度降至25.8 MPa，仅为在AUHT蒸汽条件下固化水泥浆的抗压强度的89％。根据化学结构，微观结构和孔隙结构的结果，在AUHT干燥条件下，水泥浆中形成的硬硅钙石及其微观结构从“网状”和“散状”变为“高孔海绵状组装体”，从而增加了水泥浆的孔隙率降低了其抗压强度。在AUHT蒸汽条件下，形成了一些新产品，从而增加了水合产品的总含量并保持了其“整体”微观结构。因此，在AUHT蒸汽条件下固化的水泥浆的孔隙率低于在AUHT干燥条件下固化的水泥浆的孔隙率，