Influência de variações construtivas no isolamento acústico de alvenarias: falhas construtivas e instalações

The estimative of acoustic isolation on construction systems constitute an important step of specification in the edification project. However, little changes can compromise the acoustic performance and reduce the efficiency of a defined solution before the construction starts. The construction system is composed not just of the materials that constitute the element, but also of the constructive method. Beyond the construction system, the form that the construction is thought, in its conception, can end up influencing in its performance; often, causing unforeseen events not observed by those responsible for the project. The objective of this article was to analyze the acoustic performance of a vertical masonry fence, composed of 12 horizontal holes and 19cm thick bricks with a 2.5cm mortar coating on both sides. 15 samples were tested, with variations that involved the filling of vertical joints, the type of wedge and the different alignment of electrical installation boxes. The tests were performed in the field, using the method described in the norm ISO 16283-1: 2018. The results obtained indicate that a difference of up to 4 dB can be seen between the sample with correct execution and the sample with the highest number of failures. The most significant variation was the comparison of the same wall configuration, one with vertical joints of the filled blocks and the other without the filled vertical joints of the blocks. It can also be seen that the acoustic insulation of a masonry wall loses its efficiency more significantly when a set of failures occurs in the same construction system.