Isolamento do ruído de impacto entre pisos de unidades habitacionais sobrepostas através da aplicação de novo revestimento sobre o piso original

Abstract

The requirements concerning of insulation the noise levels of impact in the system of floors between adjacent units of multi-storey residential buildings in Brazil, were established in the Performance Standard, NBR 15575-3 (ABNT, 2013). Since then, new construction must conform to the limits set by performing three ranges: low (between 66 dB and 80 dB), intermediate (between 56 dB and 65 dB) and upper (less than or equal to 55 dB). In this work, we discuss the results of a study that aims to seek an alternative to correct the impact noise problems on the floor in buildings already completed, also reaching those built prior to the effectiveness of the standard. The idea is to evaluate the efficiency of impact noise attenuation between floors of overlapping housing units by applying a new coating on the original floor. The tests were simulated in two acoustic chambers, one with structural slabs of the conventional precast type and the other with ribbed slab. Also measurements were made on the field in multi-floor building, constructed with precast slab lattice. The simulation of the tests was with the application of new coatings (wood laminate, extra fine porcelain tile or ceramic) on original ceramic floor. The wood laminate was tested as a new floor with different resilient materials between it and the original ceramic floor: the original laminate supplier's blanket and the commercial acoustic mat produced with recyclable PET bottle material. Floor systems of tested flor resulted in a maximum increase of only 1.6 cm in total thickness. The extra fine porcelain tile or the ceramic on the original floor were used without any resilient material between them. The extra fine porcelain or ceramic on the original floor were used without any resilient material between them. From the results obtained with the original ceramic floor, whose weighted standard impact sound pressure level (L'nT,w) was equal to 81 dB (conventional preformed slab in the laboratory), 79 dB (laboratory ribbed slab) and 78 dB (pre-cast lattice in the field), a 25 dB reduction was observed in the L'nT,w, when the commercial acoustic and wooden laminate was used as a new floor for both laboratory tests with the two types of slab, and 28 dB reduction in the field test. The performance range of each original floor was changed differently, when compared to the respective new floor systems on original floor. The highlight was the change from minimum to higher performance in the field test, in which a blanket was used between the wood laminate and the original ceramic floor. When the extra-fine porcelain tile floor was used on the original floor, tested only in the laboratory the performance change was for intermediate. With the ceramic flooring on the original floor, also tested only in the laboratory, the reduction of the L'nT,w was so low that it maintained the same minimum performance of the floor system. Based on the results, it can be stated that the idea of implementing a new coating on the original floor has the potential to correct floor impact noise problems between overlapping buildings. The systems, tested using resilient materials between the wood laminate and the original ceramic floor, stand out as those with better acoustic isolation to impact noise, with small increase in the final thickness of the system.