Experimental investigation of temperature distribution in massive concrete using fiber optic sensing technology

Concrete dams are among the most frequently monitored structures due to their long lifespan and catastrophic consequences associated with failure. Recently, advancements in material science and instrumentation have led to substantial progress in monitoring techniques for evaluating dam integrity. This research focuses on the monitoring of temperature development in massive concrete structures - an important parameter for predicting the mechanical properties of concrete. Conventional monitoring techniques primarily utilize discrete-point sensors, which provide limited spatial resolution and are often insufficient for accurately capturing the complexity of temperature distribution. To overcome these limitations, distributed (linear) temperature sensing using the fiber optic cables, has emerged as an effective alternative, enabling continuous temperature measurement along the length of the sensor. This paper presents the principles of distributed fiber optic sensing for temperature monitoring in massive concrete structures and illustrates its practical implementation during the hydration phase of concrete placement in a real structural block. • Nondestructive monitoring of temperatures in concrete structure with optical fibers • High-resolution temperature profiling at numerous points within concrete element • Possibility of identification of structural and material anomalies • Demonstrated applicability on a large-scale real concrete gravity dam