古建筑灰浆材料早期硬化过程的核磁共振实验研究

Nuclear Magnetic Resonance Imaging Research of Early Condensation Process of Traditional Mortar Materials

古建筑灰浆硬化过程中的含水率、孔径尺寸变化对灰浆的强度和性能的评价具有重要价值和意义,而目前由于技术的限制使开展建筑现场灰浆硬化过程的实时监测存在困难,因此对于灰浆强度和质量的评价多采用室内有损检测的方法。通过对硬化过程开展核磁共振技术应用试验,采用低场核磁T2谱和核磁成像在线技术,测量灰浆凝固过程中影响灰浆质量和性能的孔隙率、孔径分布、含水量及水态转换等重要指标,实时获取灰浆材料孔径分布、含水量的一维信息及二维成像数据,分析灰浆初始状态以及养护180 h的微细结构图像,揭示二元灰土孔隙结构及含水量随灰浆硬化的演化情况,以揭示灰浆硬化机制。灰浆硬化过程核磁共振在线观察试验很好地解释了宏观试验所得出的双组分材料相互作用、孔隙演化、水分迁移及水性转换等现象,为灰浆材料硬化过程及硬化机制解读提供了新的手段,为古建筑修补灰浆的筛选评估提供了评价技术。

Porosity and water content during condensation process of mortar are important parameters to evaluate the strength and quality of mortar.But at present,due to technical limitation,it is difficult to carry out real-time monitoring of mortar in the construction site and indoor damage detection is used to evaluate property of mortar.The low-field nuclear magnetic T2 spectrum and nuclear magnetic imaging on-line technology were used to analyze fine structure image of the curing for 180 hours,through observing the evolution of the pore structure and water content of the binary lime soil during the hardening process of the mortar to reveal the hardening mechanism of the mortar.The nuclear magnetic resonance on-line observation test of mortar hardening process explains the two-component material interaction,pore evolution,water migration and water-conversion phenomenon obtained by macroscopic experiments,which provides a new means to explain the hardening process and hardening mechanism of mortar materials and a repairing material screening technology of ancient building.