In the civil engineering construction field , it is not only necessary to build up structures as per plan , but also to be sure that with age the building is performing the same as estimated. For this , building assessment is a necessary factor. In this generation , equal importance is given for both building construction study as well as building evaluation studies. This has led to much sophisticated , but accurate methods to evaluate the present structural condition of the building , to save it for the future.
Infrared Thermography is such a great innovation which help in the investigation of what condition the building is in and guide in damage fixing. This method is a kind of non-destructive method which evaluates without any contact. They have a huge demand to carry out rapid investigations. But its prominence in building investigation is still growing.
The method of infrared thermography involves the data acquisition and its analysis with the help of thermal imaging devices that works without any contact with the material to be analyzed. With years , the method has been developed into more proficient manner as excellent infrared cameras were developed , that supports the method by converting the radiations into images (thermal images).
The concept of working is simple. The method involves the conversion of infrared radiations that are emitted (by the body under observation) into thermal images or thermographs. Thermography means writing with heat. The data is obtained from the material observed based on the thermal radiation emitted by them. The characteristics of the radiation emitted are based on the body temperature , their surface condition as well their thermal properties.
An infrared camera here has the role in sensing the thermal energy from the body. The emitted energy may be due to reflection or transmission or directly radiated energies. This sensed data is converted into thermographs or thermal images. These only bring the results based on the radiant energy and no visible light is considered. Thermal images are entirely different from visual images. These images can be taken under total darkness.
One of the main application of infrared thermography in the civil engineering is depended on the construction thermography. As the results are based on the emission properties of the materials , a good assessment of that area has to be performed. The emission properties of building materials are represented in terms of emission coefficients , which mainly range between 0.90 and 0.96.
The Infrared thermography possesses a wide variety of application in the civil engineering field , including deterioration of moisture penetration , plumbing assessment , determination of fresh and hardened concrete , accurate tension test of rebar , and determination and location of voids in concrete.