Retrofitting masonry and cavity brick façades for different noise zones using laboratory measurements

Abstract

Façade airborne sound insulation is crucial for protection of indoor environment from environmental noise. In Turkey, sound insulation in new buildings is bound by law, but 6 million pre-1980 dwellings with thin brick walls and single-glazed windows used in highly transparent façades should be retrofitted. In this study, sound reduction index of masonry and cavity exterior walls which consist of brick, mortar, gypsum board and mineral wool and of common window types is measured in sound insulation test rooms. The study compares and evaluates the effects of plaster, brick thickness, cavity depth, mineral wool thickness and mineral wool placement on sound reduction index values, using traditional materials and building techniques. Traditional brick wall façades and possible retrofitting of these façades are evaluated for sound insulation of bedrooms and living rooms in different noise zones, 55, 60, 65, 70 and 75 dBA, with various transparency ratios, 0%, 30%, 40%, 50% and 70%. The analysis shows that window types and single-layer walls are the deterministic factors in evaluating sound insulation in retrofitting projects and that it is not possible to provide proper aural comfort in high noise zones.

Acoustic performance of brick masonry walls: Construction defects and influence of installations

“…7 These variations make the materials lose uniformity, mainly on systems that require construction of some sorts of plate and/or inclusion of boxes in masonry, for which small gaps with variable measures make the theoretical estimations impracticable. 8…”

A methodology to determine appropriate façade aperture sizes considering comfort and performance criteria: A primary school classroom case

“…Instead, the element with the lowest sound insulation performance is the main determining factor in the results. 59 In this case, because the window is the acoustically weak element, changing the insulation materials in the wall did not have a significant influence. The area of the weak element, in other words, aperture size, was effective in sound insulation results.…”

“…D 2m,nT , was calculated through sound reduction index, R. 55 For this study, laboratory sound reduction index measurements, R and R w (C tr ), 57,58 made in Turkey using local building elements were used. 59 In the case of multiple façade parts, such as transparent and opaque elements or openings, the sound reduction index of the composite façade was calculated through logarithmic calculation. 55 These composite façade sound insulation values were validated on-site in a measurement study involving multiple case measurements of façade insulations against traffic noise in Istanbul city.…”

A critical review of acoustic modeling and research on building façade

“…Some researches opted to study the acoustic characteristics of a façade in laboratories. 37 –52 Díaz and Pedrero 37 and Díaz et al 38 experimentally investigated the effect of rolling shutters and shutter boxes on the sound insulation properties of a façade window. The study contained a summary of sound insulation from airborne noise in several types of windows with a built-in shutter and prefabricated box.…”