DESEMPENHO ACÚSTICO DE PAREDES DE ALVENARIA COM VERMICULITA EXPANDIDA

Abstract

Masonry is a constructive system consisting of a cohesive and rigid set of units (blocks or bricks) joined by some bonding material. This constructive system is widely used in Civil Construction and, in order not to overload the structure, it has been using hollow blocks instead of massif blocks, which reduce the cost and increase the thermal insulation. On the other hand, these cavities decrease the system’s surface mass and increase the internal resonances in the blocks, damaging the sound insulation. To minimize this effect, the cavities of the blocks may be filled with porous material, where expanded vermiculite is a material with potential for this purpose. Thus, this study aimed to evaluate the influence of the usage of expanded vermiculite in the filling of cavities of ceramic blocks with different thickness in masonry walls to increase the acoustic insulation of these constructive systems, by means of tests of sound transmission loss, following the parameters of ISO 10140: 2010, seeking a correlation between the obtained results and the superficial mass of these walls’ typologies. The results obtained from the tests were by bands of octave-thirds and weighed values. Through the tests performed, it was verified a correlation between the improvement of the acoustic performance and the systems’ superficial mass, where the greater values of insulation were obtained in specimens which received internal and external revetment of cementitious material, such as the samples 9A, 11,5B and 14A, obtaining a Rw of 50 dB. Apart from that, it was noted a damping phenomenon produced by the vermiculite in the generated insulation curve, which is in consonance with what is expected of a granular material used as filling input in cavities of ceramic blocks in order to damp the systems’ internal resonances.