Experimental tesearch on the physicochemical behavior of high strength concrete in high temperature environment by using the TNRF focusing on the local moisture behavior

剥落现象的物理化学过程被认为是与孔隙结构内的水汽压力增加、受抑的热相互作用或两者同时作用有关。此外，高温下脱水水对水泥水化产物CSH和水化钙的影响也不容忽视。在本研究中，我们应用中子射线照相技术检测了高温下高强混凝土的水化行为，以了解高强混凝土的剥落现象，重点研究了配合比和干燥条件的差异。用中子照相技术可以观察到普通混凝土的剥落时刻，通过对图像的强度分析，可以了解火灾条件下混凝土的受潮行为。此外，TNRF的结果清楚地表明，在100摄氏度的温度下，水在该地区凝结为湿气堵塞。

The physico-chemical process of the spalling phenomena is assumed to be doe to the moisture pressure build-up inside the pore structures, restrained thermal interaction or simultaneous action of both. Also, it can't be ignored that the influence of dehydrated water under high temperatures from cement hydrate, such as CSH and calcium hydrate.In this research, we applied neutron radiography to detect the hydraulic behavior under high temperatures to understand the spalling phenomenon of high strength concrete, focusing on the difference of mix proportions and dryconditions. The moment of spallation of ordinary concrete can be observed by the neutron radiography, and the moisture behavior under the fire condition can be examined by the intensity analysis of the images. And also, the result by TNRF clearly showed that water condensed as moisture clog in the region at a temperature of 100 degrees Celsius.