In karst areas, the water inflow in underground pipelines often shows the features of large and high flow rate that is extremely difficult to treat. Due to long hardening time, poor bonding of the interface and low retained rates during dynamic water filling, the ordinary inorganic grouting materials are easy to lead to sealing failure. Magnesium phosphate cement has the characteristics of good interfacial bond and quick solidification, which is very appropriate for karst piping sealing. In the study, a water-resistant scour grouting material based on potassium dihydrogen phosphate, light burnt magnesium oxide, metakaolin, sodium silicate, and bentonite is developed. This grouting material is a modification of potassium magnesium phosphate cement and some of the MgO and KH₂PO₄ is replaced by metakaolin (0–30%). Then, these three materials make up the gel material system. The fresh grouts designed water-binder ratio is 1 and the material is sodium silicate and (0–6%) modified with bentonite (10%). The properties of the grouting material including compressive strength and bending strength (after 1 day, 3 days, 7 days, 14 days, and 28 days), setting time, viscosity, and flow distance are studied. We used X-ray diffraction and scanning electron microscope to study the microscopic properties of a hardened grouts. Our experimental results show that the MgO/KH₂PO₄ (molar ratio), sodium silicate and metakaolin affect the compressive strength, bending strength, gel time, and viscosity of the grouting material. The addition of metakaolin reduces the early strength and the fluidity of the grouting materials, but the grout with 20% metakaolin has a higher 28-day strength. The sodium silicate reduces the setting time and rheological property of the grouting materials but increases their strength.

在喀斯特地区，地下管线中的水流入常常表现出大流量和高流量的特征，这是极难处理的。由于动态水灌装过程中硬化时间长，界面粘结性差和保留率低，普通无机灌浆材料容易导致密封失败。磷酸镁水泥具有良好的界面结合和快速固化的特点，非常适合岩溶管道的密封。在研究中，开发了一种基于磷酸二氢钾，轻烧氧化镁，偏高岭土，硅酸钠和膨润土的防水冲刷灌浆材料。这种灌浆材料是对磷酸钾镁水泥和一些MgO和KH ₂ PO ₄的改性被偏高岭土（0–30％）取代。然后，这三种材料组成了凝胶材料系统。新鲜的水泥浆设计的水结合剂比率为1，材料为硅酸钠和（0-6％）的膨润土（10％）改性。研究了灌浆材料的特性，包括抗压强度和抗弯强度（1天，3天，7天，14天和28天之后），凝固时间，粘度和流动距离。我们使用X射线衍射和扫描电子显微镜研究硬化水泥浆的微观特性。我们的实验结果表明，MgO / KH ₂ PO ₄（摩尔比），硅酸钠和偏高岭土会影响灌浆材料的抗压强度，弯曲强度，胶凝时间和粘度。偏高岭土的添加降低了灌浆材料的早期强度和流动性，但是含有20％偏高岭土的灌浆具有更高的28天强度。硅酸钠减少了灌浆材料的凝固时间和流变性，但增加了其强度。