The transmission and distribution of moisture in cement-based materials are of great significance to the properties and durability of materials. Traditional macro-humidity monitoring equipment in civil engineering cannot capture the microscale humidity inside cement-based materials in situ. In this paper, a method of using rhodamine 6G fluorescence to characterize the change in relative humidity in cement-based materials is proposed. Two kinds of moulding processes are designed, which are premixed and smeared after moulding, and the optimal preparation concentration is explored. The results showed that rhodamine 6G can reflect the relative humidity of cement-based materials in situ by its fluorescence intensity and had little effect on the hydration heat release and hydration products of cement-based materials; the fluorescence intensity was much higher when the internal relative humidity was 63% and 75%. The research results lead the application of polymer materials in the field of traditional building materials, help to explore the performance evolution law of cement-based materials in micro scale, and have important significance for the evolution from single discipline to interdisciplinary.

水泥基材料中水分的传递和分布对材料的性能和耐久性具有重要意义。土木工程中传统的宏观湿度监测设备无法就地捕获水泥基材料内部的微量湿度。本文提出了一种使用罗丹明6G荧光表征水泥基材料中相对湿度变化的方法。设计了两种成型工艺，分别在成型后进行预混合和涂抹，并探索最佳的制备浓度。结果表明，若丹明6G可以通过荧光强度原位反映水泥基材料的相对湿度，而对水泥基材料的水化放热和水合产物影响不大。当内部相对湿度分别为63％和75％时，荧光强度要高得多。研究成果引领了高分子材料在传统建材领域的应用，有助于探索水泥基材料微观尺度的性能演化规律，对从单一学科到跨学科的演化具有重要意义。