Traffic noise has long been a concern for federal, state, and local entities, prompting the first sound barrier to be constructed in 1963. Over time, there’s been significant advancements in the concept, design and implementation of sound walls. And while highway sound management is a leading application for concrete walls, there are also a number of reasons why this type of fencing is important and highly beneficial for both facility security and community safety.
Today’s precast concrete walls are highly impenetrable, making them one of the most heavy-duty security fencing systems available. These structures are nearly impossible to scale and can withstand winds of hurricane proportions. Their sound reduction capabilities make them ideal solutions for highway needs, and their strength and security features render them ideal choices for applications in government and municipal properties, critical infrastructure and the commercial landscape.
Dynamics of Precast Concrete
The installation of precast concrete sound walls involves foundations being drilled and set for concrete posts and then placing premade concrete panels in between. Contrary to concrete that is poured at the site of an application, the precasting process supports a more viable concrete product at a greater cost benefit. Precast concrete has become a predominant choice for many applications, and walls of this construction are widely employed for their security, soundproofing, structural, aesthetic and cost-efficiency benefits.
Many precast concrete walls, especially those constructed for federal and state Departments of Transportation, are produced in plants certified by the Architectural Precast Association (APA) or the National Precast Concrete Association (NPCA). They are manufactured in a supervised environment by highly qualified and experienced technicians, rendering a high standard of quality for the final product.
Because the concrete pouring is performed on a level surface, this gives the precast walls unmatched evenness and uniformity. Plus, many factors affecting the quality of cast-in-place concrete sound walls that are typically found on a job site (i.e., temperature, improper curing, craftsmanship, material quality, form joints and ties) are nearly eliminated in a plant environment.
The Science of Sound
Concrete provides an excellent sound barrier when noise is a consideration. As mentioned, this makes it especially effective for minimizing sound pollution when applied to highway fencing. There are two types of sound barriers used along highways:
- A reflective wall, which serves to block sound waves and reflect them back to the area from which they came. The perceived noise does not disappear, but it is significantly reduced due to the increased distance the noise must travel.
- An absorptive wall, made from porous and textured materials to help intercept and absorb the sound waves.
Precast concrete walls can lessen perceived noise by as much as half, significantly detracting highway sounds from surrounding areas. Engineers can even use modeling software to determine the best height and length of concrete sound walls to effectively minimize noise levels.
Sound Walls that Serve Security Needs
Precast concrete walls are perhaps the most impenetrable form of high-security fencing, so in addition to highways applications, they may also be leveraged for schools, prisons, embassies and military installations, airports, government facilities, stadiums, retail properties, real estate developments, utility substations, power and chemical plants, and more.
The fact is precast concrete sound walls serve double duty as security fortification, given that they’re nearly impossible to scale and have the unique advantage of being bullet resistant. When combined with other security features, like barbed/razor wire and video surveillance, precast concrete walls support a formidable defense against outside threats.
A top feature of this type of wall is its overall strength, which gradually increases over time and is resistant to deterioration in the face of harsh environments. Whereas other types of materials are susceptible to deteriorating, experiencing creep and stress relaxation, losing strength and/or deflecting, precast concrete is not. It can also withstand vehicular impacts and does not require protective coatings. Steel rebar or reinforcing mesh can be applied to create greater bonding of the material and prevent cracks. Post-installation, these types of walls require minimal maintenance.
A Contributor to Community Safety
On top of protecting communities from the harsh realities of noise pollution, as well as supporting some of the government and infrastructure security applications that play a role in community safety, another way precast concrete sound walls contribute to this effort is through environmental friendliness. The nature of precast concrete is that it is nontoxic and made from all-natural materials. Absorptive treatments rely on recycled materials (think: shredded tires and wood byproducts from the lumber industry) to produce the porous finish necessary for effective sound absorption.
Given the high thermal mass of concrete, it also has the capacity to absorb thermal energy, which is an advantage in controlling heat and cold in applicable settings. That could equate to less excess energy deployed to maintain temperatures. In addition, the fact that precast concrete walls are manufactured in a plant means there’s less disturbance to the actual work site and surrounding ecology.
And since precast concrete walls are manufactured in advance of installation, they can be easily installed with a small crew and overhead crane, thereby minimizing disruption to traffic. Other uses for precast concrete walls that support community safety include roadway boundaries and crash barriers, prevention of rockfall from reaching potential traffic, fauna containment from the movement of vehicles, and bridge safety.
Expert Design & Installation for Optimal Outcomes
Whether precast concrete sound walls are being harnessed for highway needs, facility security or other applications that impact the community, the design and installation process must be handled at the highest level of expertise and safety. This type of project requires no less than expert recommendations on specific structural elements and site grading concerns, as well as creative solutions and the best methods to employ based on an evaluation of site-specific details.
There’s simply no substitute for securing a valuable partnership with a qualified, experienced company that will manage the job in accordance with proper standards for safety, security, preventative maintenance and OSHA compliance. RFI’s more than 60 years of combined experience in the fencing industry make us a qualified contractor for projects involving the design and installation of precast concrete sound walls. We have been proud to partner with both PennDOT and the PA Turnpike Commission on continued highway fencing and wall needs that serve the public in such an essential way. Since 2016, we have partnered with utility companies in Pennsylvania to upgrade the security around their facilities with concrete wall fences.
Download our latest whitepaper, High-Security Fencing Systems: What You Need To Know Before You Install, to get key tips on purchasing the right security solution for your facility.