1. The origin of the sound barrier.
A sound barrier, often called an acoustic barrier, is a structure designed to reduce the impact of noise from traffic, industrial activities, or other environmental sources. It works by blocking the direct path of sound waves, thereby lowering the noise levels experienced in nearby areas. Sound barriers are commonly used along highways, railroads, and industrial sites to protect residential and commercial areas from excessive noise.
The concept of sound barriers, also known as noise barriers or acoustic barriers, has its origins in efforts to mitigate the impact of noise pollution from various sources such as transportation, industrial activities, and urban development. The use of physical barriers to reduce noise transmission dates back to ancient civilizations where natural elements like earth berms were used to deflect and absorb sound.
In modern times, the development of sound barrier technology gained momentum during the 20th century with the rapid expansion of road and rail networks, leading to increased concerns about the impact of traffic noise on surrounding communities. The first systematic research into highway noise mitigation measures began in the mid-20th century.
One pioneering example is the construction of a wooden noise barrier along a highway in Pasadena, California in 194. This early application demonstrated that physical structures could effectively diminish traffic-related noise for nearby residents.
Over time, advancements in materials science and engineering led to the development of more sophisticated sound barrier solutions using materials such as concrete, metal, plastics, and composites. These barriers are designed not only to block direct sound waves but also to reflect and absorb them.
Today, sound barriers are integral components of urban planning and infrastructure projects aimed at managing environmental acoustics. They are utilized along highways, railways, industrial sites, residential areas near airports or other noisy facilities, and even within buildings for interior acoustic control.
2. Noise reduction principle of sound barrier
The main principle behind the effectiveness of sound barriers in reducing noise is based on the physical properties of materials and their ability to block, absorb, or reflect sound waves. When a sound wave encounters a solid object such as a barrier, several processes can occur to reduce its impact:
- Blocking: Sound barriers physically obstruct the direct transmission of sound waves from the noise source to the receiver (e.g., nearby homes or offices). This prevents some portion of the noise from reaching its destination.
- Absorption: Certain materials used in sound barriers, such as acoustic foam or acoustic fiberglass wool or acoustic rockwool or porous concrete, have the ability to absorb sound energy. When a sound wave strikes these materials, they convert some of that energy into heat through friction and internal vibrations, thereby diminishing the intensity of the transmitted noise.
- Reflection: Sound barriers can also reflect incoming sound waves away from sensitive areas by redirecting them upwards or sideways. This process helps prevent direct exposure to excessive noise levels.
The combination of these mechanisms allows well-designed and properly installed sound barriers to significantly reduce environmental noise pollution around highways, railways, industrial facilities, and other noisy environments.
3 . The main types of the sound barrier in the world.
There are several different types of sound barriers used for noise reduction around the world. Some common types include:
- Absorptive Sound Barriers: These barriers are made of materials designed to absorb sound energy, such as porous concrete, fiberglass, or specially designed acoustic panels. They are effective at reducing noise by absorbing and dissipating sound waves.
Reflective Sound Barriers: These barriers work by reflecting sound waves away from sensitive areas, using solid surfaces to redirect the noise. They are often made of rigid materials like concrete or metal.
- Transparent Sound Barriers: These barriers use transparent materials like acrylic or polycarbonate to provide visual transparency while still offering noise reduction benefits.
- Vegetative Sound Barriers: Living plant-based barriers such as hedges and trees can also act as natural sound absorbers and deflectors, providing a green alternative to traditional barrier options.
- Earth Berms: An earth berm is a raised mound of soil that can act as a barrier by obstructing direct transmission paths for noise and absorbing some amount of sound energy.
These are just a few examples, but there may be various other specialized types developed for specific applications or environmental conditions. Each type has its own advantages and limitations depending on factors such as cost, aesthetics, effectiveness in reducing specific frequencies of noise, and ease of installation and maintenance.
4. The standards of the test about the sound barrier walls
ASTM C423-22 is the newest standard test method for sound absorption and sound absorption coefficients by the reverberation room method. It is used to measure the sound absorption characteristics of materials such as acoustic ceiling tiles, wall panels, and other building components.
This standard is mainly used in the United States. The ASTM (American Society for Testing and Materials) develops and publishes technical standards for a wide range of materials, products, systems, and services. Therefore, ASTM C423-22 would primarily be used in the U.S. However, it may also be recognized or adopted by other countries or industries that follow ASTM standards or have similar testing requirements.
HORSEN 32mm thin noise barrier (also called temporary noise barrier) has got the test reports which is issured by TUV SUD Singapore. The STC of HORSEN thin noise barrier is 28db and NRC is 0.75.
Horsen 100mm/80mm thick noise barrier(also called permanent noise barrier)has got the test reports which is issued by TUV SUD China. The STC of Horsen thick noise barrier is 37db and NRC is 0.97
5. Horsen Noise Barrier
Horsen offeres two main system noise barrier.
- One type is thin noise barrier system(also called temporary noise barrier). This system noise barrier is always used in worksite in Singapore and Malaysia market for the MRT and LTA projects. Since the surface of the screen can be spray-painted with colors, during the design process, the final installation effect can be designed into various patterns according to the needs of the urban landscape, such as cartoon character patterns, big tree patterns, etc.
This kind of temporary sound barrier not only has the effect of reducing noise, but also plays an icing on the cake effect on the urban landscape.It can be 6m,8m and 12m high after installation. It includes: jagged panels(on top), common panels, transparent panels, H bar, top runner bar, big H post ,scaffolding and accessories. The big H post to be used as the main support, the scaffolding as the support frame. H bar is used to connect the panels. Top runner bar is used to connect the top jaddged panels with the common panels.
The materials of the thin(temporary)noise barrier is galvanized louver punching sheet and PVC painting on surface. It can be any color. The inside of the panels is filled with fiberglass wool. This temporary noise barrier is flexible, it also can be recycled with a typical service life of 3 years. And it is also light, and can be easily installed.
- The other type is thick noise barrier system(also called permanent noise barrier).This sound barrier system has a very wide range of applications in the field of sound insulation and noise reduction. It is popular used in railway, roadway,overpass, school, industy and so on. The reason why this system called permanent noise barrier is it can not be recycled. Once it is installed, it can be 30 years service life.
The whole noise barrier system includes: thick panels(80mm or 100mm), H post, panel cover and PMMA(acrylic) transparent panels. The materials of the thick panels can be galvanized or aluminum sheet and the hole can be louver hole and round hole. The surface is PVC spray painting, and the color can be RAL colors.And the inside of the panels is filled with fiberglass wool. The height after installation can be 3m, 4m,5m. The sound barrier of this system is generally installed with thick galvanized or aluminum panels at the bottom and top, and a transparent panels in the middle. The transparent panel in the middle is to create a broad field of vision for the driver to relieve boredom and fatigue during driving.This system noise barrier is widely used all over the world.
Horsen noise barrier is one of the leading noise barrier exporters from China, if you have any need of the sound barrier, please feel free to contact : admin@betternoisebarrier.com or Whatsapp: 008617331233551 or Wechat:008615931259551
