高强混凝土受压损伤过程红外辐射特征试验研究

Test Study on the Infrared Radiation Features of High Strength Concrete during Fracturing Process under Pressure

利用红外热像仪观测高强混凝土试件加载过程中红外热辐射情况,研究高速铁路无砟轨道及基础工程混凝土结构受压损伤过程红外辐射特征。结果表明:混凝土试件在荷载作用下向外辐射的红外热量随应力增加而增加;加载初期试件表面温度均匀上升,中期低温区存在升温-降温-再升温的反复过程,加载后期温度上升速度加快,临近失稳前存在短暂的降温过程;整个试件加载破坏过程,高温区域包围低温区域的温度场是热像的主要特征;试块在破裂前,其红外热像会出现清晰的"高低温边界线"。因此利用红外热像技术,可对高速铁路无砟轨道及基础工程混凝土的损伤进行红外无损检测和安全监测。

Infrared thermal radiation of high strength concrete specimen under loading was observed by infrared thermography to research the infrared radiation features of concrete structure of ballastless track and foundation concrete of high-speed railway during fracturing process under pressure.The results show that the infrared heat radiated outward from concrete specimen under loading increases with stress.During the initial stage of loading,the temperature of specimen surface rises evenly.During the intermediate stage of loading,there is a repetitive process of heating-cooling-heating in low temperature region.The temperature rises rapidly during the later stage of loading.Before approaching the instability of specimen,there is a brief cooling process.During whole loading process,the phenomenon of lower temperature area surrounded by high temperature area is the main feature of thermal images.Before the fracture of specimen,some clear lines appear in the infrared thermal images between high and low temperature zones.Therefore,the technology of infrared thermal imaging can be used for non-destructive test and safety monitoring of high-speed railway ballastless track and foundation concrete.