<div><div><div><p>Tonal sounds are a particular problem of concern in building environments, arising from the widely used rotating machinery (e.g., compressors, fans, motors, trans- formers, etc.). In the recent trend of designing and manufacturing high-performance building mechanical systems, higher output power and higher rotation speed are pursued, this inevitably results in a more severe noise problem, since the equipment noise not only becomes louder but also shifts to a higher frequency region (which, in most cases, results in a poorer sound quality due to the shift in spectral balance and tonal components moving into the frequency regions where people are most sensitive to tones). Tonal sounds from rotary machines can be annoying, even at relative low levels.</p><p>Currently, noise criteria guidelines in Chapter 48 of the ASHRAE HVAC Applications Handbook can be used to design the building mechanical system, but this does not apply well for tonal noise. Reducing the limit for noise with perceptible tones is one common strategy in the industry. However, it’s not adequate for some cases, over-design in others. Thus, an adequate understanding of the annoyance threshold of tonal noises associated with building services equipment is valuable technical information not only in the design and manufacture of machines but also in the development of noise regulations related to building services equipment.</p><p>This research aims to develop a sound quality model that cooperates with sound level and tonalness and relates tonal building noises to the perceived annoyance.</p></div></div></div>

As betoneiras, embora sejam equipamentos aparentemente inofensivos e que não trazem muitos riscos aos trabalhadores, esconde um problema muito grave associado à sua operação, que são os altos níveis de ruído produzido. Normalmente os operadores de betoneiras são aqueles que ficam mais expostos a estes elevados níveis de ruído e, também há os demais operadores e a vizinhança. Esta pesquisa, além de quantificar tais impactos, sugere formas para amenizar os níveis de ruído assimilados por estes operadores de betoneiras e que são provenientes deste equipamento, atuando na fonte geradora. Para minimização do nível de ruído, foi desenvolvida tampa de proteção para ser utilizada na boca do tambor, de modo que não interferisse no modo de operação da betoneira e que também servisse para atenuar o ruído durante a mistura do agregado. Foi objeto de estudo a análise e aplicação de dois materiais, sendo eles placas de EVA e borracha líquida, para revestimento do tambor da betoneira, que contribuísse para a redução do nível de ruído. Os níveis de pressão sonora equivalente foram coletados na frente, atrás e nas laterais da betoneira a distâncias de 1 a 8 metros. Os resultados demonstraram que é possível minimizar o ruído garantindo um conforto acústico durante o uso da betoneira em um canteiro de obras. Os ensaios comprovaram que, dentre as opções analisadas, o melhor revestimento é a borracha líquida que pode ser utilizada externamente ao tambor da betoneira reduzindo o ruído em 13 dB(A), chegando a 17 dB(A), com o uso da tampa de proteção. / The concrete mixers, although seemingly harmless and equipment that do not bring many risks to workers, hides a very serious problem associated with their operation, which are the high levels of noise produced. Usually the mixers operators are those that are more exposed to these high levels of noise and there are also other operators and the neighborhood. This research and to quantify these impacts, suggests ways to mitigate the noise levels assimilated by these mixers operators and discharged from this equipment, acting at the source. To minimize the noise level cap has been developed for use in the mouth of the barrel, so it does not interfere with the mixer operating mode and also serve to reduce the noise when mixing the aggregate. Object of study was the analysis and application of two materials, namely plates EVA and liquid rubber, to drum coating the mixer, which would help reduce the noise level. The equivalent sound pressure levels were collected in front, behind and on the sides of the mixer at distances 1-8 meters. The results showed that it is possible to minimize noise ensuring acoustic comfort while using the mixer on a construction site. Tests have shown that among the options considered, is the best coating liquid rubber which may be used externally to the mixer drum 13 reducing the noise in dB (A), reaching 17 dB (A) with the use of lid protection.

As betoneiras, embora sejam equipamentos aparentemente inofensivos e que não trazem muitos riscos aos trabalhadores, esconde um problema muito grave associado à sua operação, que são os altos níveis de ruído produzido. Normalmente os operadores de betoneiras são aqueles que ficam mais expostos a estes elevados níveis de ruído e, também há os demais operadores e a vizinhança. Esta pesquisa, além de quantificar tais impactos, sugere formas para amenizar os níveis de ruído assimilados por estes operadores de betoneiras e que são provenientes deste equipamento, atuando na fonte geradora. Para minimização do nível de ruído, foi desenvolvida tampa de proteção para ser utilizada na boca do tambor, de modo que não interferisse no modo de operação da betoneira e que também servisse para atenuar o ruído durante a mistura do agregado. Foi objeto de estudo a análise e aplicação de dois materiais, sendo eles placas de EVA e borracha líquida, para revestimento do tambor da betoneira, que contribuísse para a redução do nível de ruído. Os níveis de pressão sonora equivalente foram coletados na frente, atrás e nas laterais da betoneira a distâncias de 1 a 8 metros. Os resultados demonstraram que é possível minimizar o ruído garantindo um conforto acústico durante o uso da betoneira em um canteiro de obras. Os ensaios comprovaram que, dentre as opções analisadas, o melhor revestimento é a borracha líquida que pode ser utilizada externamente ao tambor da betoneira reduzindo o ruído em 13 dB(A), chegando a 17 dB(A), com o uso da tampa de proteção. / The concrete mixers, although seemingly harmless and equipment that do not bring many risks to workers, hides a very serious problem associated with their operation, which are the high levels of noise produced. Usually the mixers operators are those that are more exposed to these high levels of noise and there are also other operators and the neighborhood. This research and to quantify these impacts, suggests ways to mitigate the noise levels assimilated by these mixers operators and discharged from this equipment, acting at the source. To minimize the noise level cap has been developed for use in the mouth of the barrel, so it does not interfere with the mixer operating mode and also serve to reduce the noise when mixing the aggregate. Object of study was the analysis and application of two materials, namely plates EVA and liquid rubber, to drum coating the mixer, which would help reduce the noise level. The equivalent sound pressure levels were collected in front, behind and on the sides of the mixer at distances 1-8 meters. The results showed that it is possible to minimize noise ensuring acoustic comfort while using the mixer on a construction site. Tests have shown that among the options considered, is the best coating liquid rubber which may be used externally to the mixer drum 13 reducing the noise in dB (A), reaching 17 dB (A) with the use of lid protection.

The diploma thesis deals with the solution of selected parts of the the construction technology project of the town covered swimming pool in Luhačovice. The project includes engineering report, design site equipment and crane, technological instruction for drilled pile and piled wall, supervisory and test plans. For the substructure deals with building noise and noise protection. Next it deals with the itemized budget of the gross building and detailed time plan.

The subject of this diploma thesis is the elaboration of a construction technological project for the construction of an administrative building with garages in Prague. The building is located in an enclosed area in the Prague-Veleslavín district. The main subject of this thesis is the elaboration of a technical report, a coordination situation of the construction with broader relations of transport routes, a time and financial plan of construction - object, a study of implementation of main technological stages of building, a project of the site equipment, a design of main construction machines and mechanisms, a time plan of main building, a plan of material resources, a technological regulation for the implementation of monolithic ceiling structures, a quality control and testing plan for monolithic ceiling structures. The diploma thesis also includes the calculation of construction according to THU, a occupational health and safety plan, concreting economics, a noise study, a selected points LEED certification and a budget with site equipment costs.