Long-term storage of carbon dioxide (CO₂) inside depleted reservoirs can help reduce the impact of greenhouse gas emissions. Portland cement has been shown to degrade significantly during long-term contact with CO₂. This research aims to provide a new environmentally friendly, Class C fly ash-based cement as a potential alternative to Portland cement for CO₂ storage wells. This was achieved by comparing the mechanical degradation of Portland cement and Class C fly ash-based alkali-activated cement in a CO₂ environment. A specially designed setup was constructed to create an in situ high pressure and high-temperature CO₂ environment. Seventy-two cores of Portland cement and Class C fly ash-based cement were prepared for this study. The results show that CO₂ reacted with the water in the vessel and formed carbonic acid, which reduced the water pH to 6.8. Millimeter-sized crystals of calcium carbonate (CaCO₃) were observed on the surface of the Portland cement cores after the CO₂ exposure. The surface of the fly ash-based alkali-activated cement cores was not substantively changed after the exposure. No significant change in density was observed for both types of cement during the 14 days of CO₂ exposure. Portland cement showed a significant reduction in compressive strength, and this reduction developed as the exposure time increased. Interestingly, Class C fly ash-based cement showed no reduction in compressive strength, and only a small amount of reduction was observed after 14 days of exposure. This research compared the mechanical degradation of Portland cement and Class C fly ash-based alkali-activated cement in a high-pressure and high-temperature CO₂ environment.

在枯竭的水库中长期储存二氧化碳（CO ₂）有助于减少温室气体排放的影响。波特兰水泥已显示出在与CO ₂长期接触过程中会明显降解。这项研究旨在提供一种新型的环保，C级粉煤灰基水泥，作为波特兰水泥在CO ₂储存井中的潜在替代品。这是通过比较波特兰水泥和C级粉煤灰基碱活化水泥在CO ₂环境中的机械降解来实现的。构建了专门设计的设置以创建原位高压和高温CO ₂环境。本研究准备了72个波特兰水泥和C类粉煤灰基水泥的芯。结果表明，CO ₂与容器中的水反应并生成碳酸，从而将水的pH值降至6.8。暴露于CO ₂后，在波特兰水泥芯的表面观察到毫米大小的碳酸钙晶体（CaCO ₃）。暴露后，粉煤灰基碱活化水泥芯的表面未发生实质性变化。在CO ₂的14天中，两种水泥的密度均未观察到明显变化。接触。波特兰水泥显示出抗压强度的显着降低，并且这种降低随着暴露时间的增加而发展。有趣的是，C级粉煤灰基水泥的抗压强度没有降低，暴露14天后仅观察到少量的降低。这项研究比较了在高温高压的CO ₂环境中波特兰水泥和C级粉煤灰基碱活化水泥的机械​​降解。