Methods and stages of thermal insulation testing in construction
The main methods of testing used in construction and thermal insulation are resonant (vibration, according to) and impulse ultrasonic. The resonant test method is based on the use of minor fluctuations (longitudinal, nbsy or steep) of the entire sample as a design as a whole.
Depending on the geometric sizes and the properties of materials in the resonant method, frequencies from several Herz to several Kilortz are used. With the help of relatively simple equipment, their own (resonant) frequencies and decrees of attenuation of certain types of oscillations are determined, according to which, taking into account the volumetric mass of the material, such parameters as the dynamic elastic modulus, the shift module and the Poisson coefficient can be calculated.
The method is used mainly in laboratory conditions, since experiments should be carried out on samples of strictly defined geometric sizes – rectangular plates, beams or cylinders. However, thanks to the work, the sphere of practical application of this method has been expanded. It is also extended to large -sized construction parts and products.