This paper reports the test results on the bonding strength between magnesium ammonium phosphate cement and Portland cement. The bonded specimens were prepared by immersion in Na₂SO₄ solution. Following immersion, the surfaces and positions of fractures on the specimens were examined. SEM and an optical microscope were used to analyse changes of the interfacial microzone following different immersion periods. Microstructure changes of the magnesium ammonium phosphate cement-based interfacial microzone within the bonded mortar specimens were studied and compared with those immersed in normal conditions. The bonded mortar specimens were found to have weaker bonding strength than that of the mortar specimens in normal conditions. Under normal conditions, slight crystal morphology changes of the interfacial microzone were observed and the crystal structure appeared compact, while more noticeable changes occurred within mortar specimens immersed in Na₂SO₄ solution, with the crystal structures within them being more loose. The bonding behaviour of the magnesium ammonium phosphate cement includes mechanical bonding, mutual diffusion, and chemical bonding. Structural diagrams of the interfacial transition zone (ITZ) in different environments are also presented. Further investigations are needed to determine the performance of the bonding interface microzone of Portland cements and magnesium ammonium phosphate cements within repair materials in order to enhance the performance of cement-based composite materials for concrete repair.

本文报告了磷酸铵镁水泥与硅酸盐水泥之间粘结强度的测试结果。通过浸入Na ₂ SO ₄中制备粘合的样品解。浸没后，检查试样上的断裂表面和位置。用SEM和光学显微镜分析不同浸没时间后界面微区的变化。研究了粘结砂浆试样中磷酸镁铵水泥基界面微区的微观结构变化，并将其与正常条件下的微观结构进行了比较。发现粘结的砂浆试样的粘结强度比正常条件下的砂浆试样的粘结强度弱。在正常条件下，观察到界面微区的晶体形态发生轻微变化，并且晶体结构显得致密，而浸入Na ₂ SO _4的砂浆试样中发生了更明显的变化。溶液，其中的晶体结构更疏松。磷酸镁铵水泥的粘结行为包括机械粘结，相互扩散和化学粘结。还显示了不同环境下的界面过渡区（ITZ）的结构图。为了增强水泥基复合材料在混凝土修补中的性能，需要进一步研究以确定修补材料中的波特兰水泥和磷酸铵镁水泥的粘结界面微区的性能。