水泥水化响应纳米材料的制备及性能评价

Preparation and performance evaluation of cement hydration responsive nanomaterial

近年来,纳米材料改性技术已成为提升混凝土耐久性的发展方向,但传统纳米材料难分散、易团聚的特征导致混凝土工作性问题。针对上述传统纳米材料的问题,设计与制备了具备水溶性特征、可在水泥水化环境中自响应,且与Ca^(2+)原位反应形成纳米有机酸钙盐颗粒的新型纳米材料,研究了该纳米材料的构效关系及其对混凝土性能的影响,分析了提高混凝土耐久性的作用机理,介绍了该材料在实际工程中的应用情况。结果表明:与传统纳米材料不同,水化响应材料对混凝土工作性能和干燥收缩基本不产生影响;掺加0.9%的水化响应材料可实现混凝土氯离子电迁移系数与吸水率的显著降低,降幅达到50%以上。

In recent years, nanomaterial modification technology has become the development direction of improving the durability of concrete. However, the use of traditional nanomaterials may lead to workability issues of the concrete due to their dispersion difficulty and agglomeration. To address the problems of the traditional nanomaterials, the present research designed and prepared a new nanomaterial which has a characteristic of water-solubility, and can respond in the environment of cement hydration and react with Ca2+ to form organic acid calcium based nano particles. The present research studied the structure-function relationship of the new nanomaterial and its effect on the concrete performance. Besides, the mechanism of concrete durability improvement when using the new nanomaterial was discussed in the paper. In the end, the application of this material in practical engineering was briefly introduced. The results show that the new nanomaterial has slight influence on workability and autogenous shrinkage of concrete, which is different from the results of traditional nanomaterials, and the addition of 0.9% of the new nanomaterial with respect to the binder content can significantly reduce the chloride migration coefficient and water absorption rate of concrete by 50%.