RESEARCH OF ACOUSTIC PROPERTIES OF MATERIALS FOR FOUNDATIONS UNDER THE FLOOR

Abstract

The most important components of comfortable conditions for people on the premises of residential and public buildings are thermal (temperature) and acoustic comfort. By the regulatory documents of Ukraine, high requirements are imposed on the thermal and sound insulation qualities of external and internal building envelopes, especially on interfloor floors. While the problem of insufficient thermal protection primarily concerns floors over cold basements and passageways, poor sound insulation of floors is a problem for all apartments in high-rise buildings. This article analyzes the causes of acoustic discomfort in buildings. A person indoors is exposed to three types of noise: airborne, impact, and structural. The most difficult problem to solve is an impact noise through the floors. It is emphasized that despite the different noise sources, the mechanisms of propagation of structural and impact noise are similar ‒ through the structural elements of the building. Therefore, measures to reduce impact noise can simultaneously reduce the level of structural noise. The most common methods of reducing sound transmission through floors are analyzed. It is proposed to replace the conventional screed in the floor structure with a heat and sound-insulating screed based on a gypsum-cement-pozzolana binder. This paper considers only an acoustic aspect of the problem. According to the theory of acoustic dissipation, it is assumed that the effect of sound energy dissipation is enhanced by the introduction of aggregates into the mixture, which increases the number of structural heterogeneities and interfaces. The aggregates used in the mixture are expanded polystyrene granules, cork chips, and granular waste from the production of foam glass. In order to experimentally verify this assumption, laboratory methods and devices were developed for a comparative assessment of the soundproofing properties of the developed compositions. Based on the results of measuring the acoustic properties of the prototypes, experimental and statistical (ES) models were constructed, and the best combinations of mixture components were determined in terms of sound insulation. ES models of noise properties were used in the multi-criteria optimization of the composition of the composite mixture.