Assessing concrete density using infrared thermographic (IRT) images

This paper presents the results of a study conducted to evaluate the possibility of utilizing infrared thermography to assess the quality of concrete. Concrete specimens were prepared with varying water to cement (w/c) ratio, cement content and consolidation effort. The concrete specimens were heated and the IRT images were recorded as they cooled down. The IR thermographs indicated a good variation in the surface temperature with varying concrete composition and consolidation effort. Concrete with similar composition exhibited a greater variation in surface temperature as the consolidation effort was decreased; indicating the presence of less dense structure in the specimens prepared with low consolidation effort. An increase in the water–cement ratio also increases the temperature variation indicating a decrease in the concrete denseness. The variation in cement content also influenced the denseness of concrete as indicated by the enhanced variation in the surface temperature. Concrete specimens with cement content of 300 kg/m3 (less dense) exhibited a greater temperature variation compared to those prepared with cement content of 400 kg/m3 (more dense).