Carbonation treatment can effectively improve the performance of recycled concrete aggregate and fines due to the reactions of CO₂ with CH and C–S–H gel of cement paste. To better understand the mechanisms involved in the performance improvement, the surface properties of carbonated recycled cement paste powder (CRP) and its effect on the rheology, hydration and strength development of cement paste was studied. The results showed that during the carbonation, the surface of CRP was covered by a layer of amorphous silica gel. The generated CaCO₃ was wrapt by the silica gel and seldom exposed. The silica layer led to the poor flowability of CRP-cement paste due to that the silica gel on the surface of CRP has a strong affinity for H₂O. During the very early hydration, the silica gel dissolved and then CaCO₃ was exposed. CaCO₃ is capable of chemically absorbing Ca²⁺, which facilitated the nucleation of C–S–H nuclei and stabilized the C–S–H phase. As a result, the C–S–H grew densely, uniformly and perpendicularly on the surface of CRP. In addition, the chemically absorbing Ca²⁺ enabled the chemical bond to be formed between CaCO₃ and C–S–H. Due to increased C–S–H resulted from reactions of silica gel with CH at the interface and the stronger bond formed between CaCO₃ and C–S–H, the interface between CRP and hydration products was much stronger than that between recycled cement paste powder (RP) and hydration products.

碳酸化处理可以有效地提高再生混凝土骨料和细粉的性能，这是由于CO ₂与水泥浆的CH和C–S–H凝胶反应所致。为了更好地了解改善性能的机理，研究了碳酸再生水泥浆粉末（CRP）的表面性质及其对水泥浆流变，水化和强度发展的影响。结果表明，在碳化过程中，CRP的表面覆盖有一层无定形硅胶。产生的CaCO ₃被硅胶包裹，很少暴露。二氧化硅层导致CRP水泥浆的流动性差，这是因为CRP表面的硅胶对H ₂具有很强的亲和力O.在很早的水合作用期间，硅胶溶解，然后暴露出CaCO ₃。CaCO ₃能够化学吸收Ca ²⁺，从而促进了C–S–H核的成核并稳定了C–S–H相。结果，C–S–H在CRP表面上密集，均匀且垂直地生长。另外，化学吸收的Ca ²⁺使CaCO ₃和C–S–H之间形成化学键。由于硅胶中CH与CH的反应以及CaCO ₃之间形成的更牢固的键合，导致C–S–H增加 与C–S–H相比，CRP与水合产品之间的界面要强于再生水泥浆粉（RP）与水合产品之间的界面。