与既有混凝土黏结是自密实混凝土重要使用场景之一。为了探究沙漠砂自密实混凝土（desert sand self-compacting concrete, DSSC）与既有混凝土黏结特性，通过黏结填充、劈裂抗拉强度试验与灌砂法确定黏结破坏模式，分析混凝土类型和界面处理方式对新老混凝土黏结性能影响。利用扫描电子显微镜测定黏结界面微观形貌特征，分析黏结界面间隙宽度分布。研究表明：线型切槽界面与受力方向一致时黏结性能更强；钻孔界面比线型切槽界面效率更高、黏结强度更强、稳定性更好；低水胶比缩小黏结界面间隙，沙漠砂对黏结界面间隙缩减效果在低水胶比下更显著。

Bonding with existing concrete is one of the important application situations of self-compacting concrete. With the aim of investigating the bonding characteristics between DSSC (desert sand self-compacting concrete) and other existing concrete, the bond-casting test, bonding interface splitting tensile strength and sand-filling method was used to determinate the failure mode and analyze the influence of concrete type and interface treatment method on the bonding characteristics between old and new concrete. Scanning electron microscope was used to photograph the micro-morphological characteristics of the bonding interface and determinate the distribution of gap width. The results show that the bonding performance is stronger when the linear grooving is consistent with the loading direction. Compared with linear groove cutting, the drilling interface is more efficient in interface efficiency and bonding strength. Low water-to-cement ratio reduces the bond interface gap. The effect of desert sand on the reduction of the bond interface gap is more significant with low water-to-cement ratio.