Experimental and theoretical analysis of acoustic properties of building materials

It is undisputable that constantly increasing acoustic deterioration of environment is affecting more and more people. It is especially noticeable in urban areas, near to the places with heavy traffic, or in areas close to the airports. Since high level of ambient noise negatively influences well-being and health of people, it should be decreased in building constructions by selection of building materials with good acoustic performance. The very first step of building structures acoustic performance evaluation lies in experimental determination of materials parameters necessary for acoustic modeling, e.g. displacement, sound velocity, amplitude of input and propagated wave. In this paper, a measurement based on acoustic excitation of fired brick sample by one period of 1000 Hz and 4000 Hz sine wave and subsequent analysis of data measured by two accelerometers is introduced. The first accelerometer is used for detection of the sine wave entering the sample, whereas the second one for detection of the attenuated wave that was propagated through the sample. Sound velocity in fired brick is calculated from time shift between the first voltage peaks detected by accelerometers and amplitudes (1st voltage peaks) are compared in terms of their decrease.