This paper investigated the effects of different proportions of Portland cement addition (0–20%) on the setting time and early-age strength of solid-waste-based sulphoaluminate cement. The mechanism of hydration process was analyzed by X-ray diffraction (XRD) technology. It was found that the incorporation of Portland cement could reduce the early-age strength of the composite cement, and shorten the setting time. When the Portland cement reached 20%, the early-age strength of the composite cement was the lowest and the setting time was the shortest. The XRD analysis demonstrated that the addition of Portland cement could accelerate the hydration process of the composite cement, and the more the Portland cement was added, the faster the hydration process of the composite cement was observed. The main reason is that the addition of Portland cement could increase the alkalinity of the composite cement and promote the hydration of anhydrous calcium sulphoaluminate. This study provides an important reference for the production of solid-waste-based composite cement.

中文翻译：

---

硅酸盐水泥添加量对固体废物基硫铝酸盐水泥早期性能的影响

本文研究了不同比例的硅酸盐水泥（0-20％）对固体废物基硫铝酸盐水泥的凝结时间和早期强度的影响。通过X射线衍射（XRD）技术分析了水合过程的机理。结果表明，掺入硅酸盐水泥会降低复合水泥的早期强度，缩短凝结时间。当波特兰水泥达到20％时，复合水泥的早期强度最低，凝结时间最短。XRD分析表明，添加硅酸盐水泥可以促进复合水泥的水化过程，添加的硅酸盐水泥越多，复合水泥的水化过程越快。主要原因是加入硅酸盐水泥可以提高复合水泥的碱度，促进无水硫铝酸钙的水合作用。该研究为固体废物基复合水泥的生产提供了重要参考。