The construction industry and high-rise buildings have promoted the use of lightweight walls. In many high-rise buildings, there are often many companies or units occupying one or several floors. This determines that the space layout cannot be designed in a fixed pattern, and the flexibility of lightweight walls precisely meets the diversity of objective needs. At the same time, using lightweight walls can also reduce the weight of the building. However, the poor sound insulation performance of lightweight walls has always been a major obstacle to promoting their use. Generally, the average sound insulation of lightweight walls is about 30 dB, which is difficult to be used as partition walls. In the past, the partition walls of brick-concrete structure residential buildings were mostly 240mm thick brick walls, and their average sound insulation was about 53 dB, and the residents were generally satisfied.
To enhance the sound insulation performance of the lightweight walls, the following measures can be taken:
1. Construct a sandwich structure. That is, use porous elastic plant sound-absorbing materials to spray and compact them. For example, a lightweight wall structure with double-layer 12mm thick gypsum boards, steel keels, and 75mm hollow space filled with ultra-fine polyester fiber insulation on both sides, the average sound insulation can reach 49dB, while its unit area mass is only one-tenth of that of a 240mm thick brick wall.
2. When the thickness of the air interlayer is reduced to more than 5mm, the sound insulation can be increased by 8-10dB in most frequency bands. For example, a lightweight wall structure with 75mm thick aerated concrete boards on both sides and 75mm air space, the average sound level can reach 50dB. Filling the air interlayer with new stage sound-absorbing materials can increase the sound insulation by 2-8dB.
3. To avoid the matching effect of the lightweight walls, the quality of each layer of materials can be different to avoid the matching valley.
4. The tightness of the board joints of the lightweight walls has a significant impact on sound insulation. For double-layer boards, the joints should be staggered. For single boards, they should be plastered or jointed. For each single board, whether to apply jointing or not can differ by 12-17dB. When setting recessed electrical switch boxes and socket boxes on both sides of the three-sided wall, the positions of the settings on both sides should be staggered, and the surrounding gaps should be filled properly.