Airborne sound insulation improvement on masonry partitions using additional plasterboard layers/Muriniu konstrukciju garso izoliavimas papildomais lanksciais sluoksniais

For the purposes of accumulating knowledge of how to comply with requirements for new buildings of obligatory sound class C or enhanced acoustic comfort sound classes A and B (Lithuanian Building Technical regulations STR 2.01.07:2003), the article discusses improvement on airborne sound insulation of partitions between dwellings using additional plasterboard layers. The results of an empirical approach were obtained performing in situ measurements of the partitions of masonry from silicate blocks and expanded-clay concrete blocks. Theoretical calculations without the evaluation of flanking paths are added. The paper looks at the peculiarities of in situ measurement methods and the estimation of the limiting uncertainty of the sound reduction index. It is showed that the values of the in situ measurements of the airborne sound reduction index in accordance with requirements EN ISO 140 and EN ISO 717 series for rooms having volume higher than 50 [m.sup.3] varies depending on frequency range. It has been stated, that improvement on the weighed airborne sound reduction index in the frequency range from 100 Hz to 3150 Hz depends on the properties of additional layers and on the characteristics of the main constructions. Resonance in the low frequency range arising due to additional layers may reduce the weighed airborne sound reduction index defined in the frequency range from 50 Hz to 3150 Hz. This fact must be taken into account when designing improvement on masonry wall insulation using an additional layer in dwellings. Keywords: acoustics, in situ conditions, acoustic measurements, partitions, additional layers, airborne sound insulation improvement. Siekiant sukaupti ziniu, kaip uztikrinti nauju gyvenamuju namu atitikti privalomosios C garso klases bei padidinto akustinio komforto A ir B garso klasiu reikalavimams pagal STR 2.01.07:2003 reglamenta, teoriniais skaiciavimais bei eksperimentiniais tyrimais nustatytas butus skirianciu sienu ore sklindancio garso izoliavimo pagerejimas irengiant papildoma sienu danga. Eksperimentiniai tyrimai buvo atliekami naturinemis salygomis matuojant silikatiniu plytu ir keramzitbetonio blokeliu muro sienas. Darbe aprasyti teorinio skaiciavimo ir naturiniu matavimu modeliai vienparametriam oro garso izoliavimo rodikliui nustatyti. Parodyta, kaip naturiniu ore sklindancio garso izoliavimo matavimu rezultatai patalpose, kuriu turis didesnis nei 50 [m.sup.3], gauti grieztai laikantis ISO 140 bei ISO 717 serijos standartu rei