Precast Concrete Provides Acoustical Advantages

Photos courtesy of FGM Architects and ©2020 Darris Lee Harris Photography

When it comes to construction of a new building, one design aspect to consider is sound transmission. Acoustics play a vital role in the design of a building, and in the designer’s selection of materials to build with.

When in the design phase, architects and engineers can determine the acoustical needs of the space and then design the building to satisfy those needs. Within each building, there will be several types of spaces, each requiring its own level of acoustical performance. The building partition (floors, walls, and ceilings) of each space offers a measurable level of privacy from outside noise and the noise from physical impacts. While some surfaces must reflect sound so loudness will be adequate in all areas where listeners are located, other surfaces absorb sound to avoid echoes and sound distortion. Sound is isolated from areas it is not wanted with the appropriate building materials.

Hollowcore plank is often a selected material for the floor and ceiling/roof as it has excellent sound transmission characteristics. Footsteps, dropped objects, slammed doors, and plumbing all generate impact noise. Precast concrete offers natural sound attenuation to dampen noise for a quiet environment. This means, if you are an apartment dweller with units above you, below you, and on either side of you, and your building is constructed with precast, you won’t hear your neighbors’ television, vacuuming, footsteps, shower turning on, or weight-lifting routine.

There are two ways of dealing with sound levels: sound insulation and sound absorption. Materials with heavy mass, like precast concrete, work well with sound. For example, when Wheaton College (Illinois) needed a new concert hall, acoustics was at the top of their focus. Completed in September 2020, Mid-States Concrete Precast Wall Panels were used to create a 650-seat acoustically engineered concert hall, a choral rehearsal room, and grand lobby. Precast was the perfect choice, according to Michael Wilder, Dean of the Conservatory of Music.

“Musicians are easily distracted by sound, so as they hear sounds from other spaces, they get off track and they can’t focus the way they need to and want to,” Wilder said.

The 55 precast concrete wall panels on this project provided the sound barrier necessary for the musicians using this space.

When all is said and done, the common goal of architects, builders and building owners is to acquire as much acoustical performance for the money as possible. This gives value.

Sound Transmission Class (STC) is a numerical rating system on how well a building partition reduces the amount of noise at a given frequency that passes through. The higher the STC, the better the performance of sound insulation. An STC rating of 50 will satisfy most building code requirements. While very loud sounds such as musical instruments or stereos can be faintly heard with an STC rating of 50, 99% of the population is not annoyed by these sounds.

According to AltusGroup, of which Mid-States Concrete Industries is a member, an 8” thick CarbonCast wall panel (wythes of 2” each) with 4” of insulation will provide an STC rating of 52. This rating can be increased by adding more mass to the wall.

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This is where Mid-States Concrete Industries comes in. Precast concrete provides high mass and insulation and can be manufactured in a variety of configurations, shapes, patterns, colors, and styles to meet almost any creative and functional vision. Contact our Preconstruction team today to assist you in finding the best precast solution and maximum acoustical performance for your project.

Email Jeremy Olivotti, Vice President of Preconstruction >>

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Precast Concrete Offers Smooth Construction Process for Junior High School

When the El Paso Gridley school district passed a referendum for the construction of a new junior high school, CORE Construction got to work to get the project completed on time for the 2022-23 school year.

Construction of the project in Gridley, Illinois included an 80,000 square foot new junior high school, storm shelter, and expanded space for arts and choir students. Mid-States Concrete provided 178 wall panels, one column, and 59 pieces of hollowcore plank and solid slabs to meet the precast needs of the project.

Nicole Shelton, Project Manager with CORE Construction, found several benefits to working with Mid-States Concrete Industries for the project’s precast needs.

”From a coordination and shop drawings process, there is a lot to it, but I think Mid-States did a really nice job coordinating that alongside CORE and working with the MEP trades to make sure we had stuff cast in and openings we needed,” she said. “In terms of installing, it’s very convenient for a construction schedule and getting a building closed in quickly. It allowed us to get enclosed and work inside during the late winter months.”

Additionally, the project management team’s onsite visits ahead of construction were crucial to working through logistics.

”Mid-States was really professional and helpful,” Shelton said. “[They were] on site constantly and easy to reach during the project. All of that helped the project run smoothly.”

Even before a project begins, Shelton appreciates the communication of the Mid-States team. She likes that she can pick up the phone and speak to the preconstruction team with general questions about precast, schedule, how it all works and get the details she needs to help her prepare for future projects.

”I’ve always been impressed by Mid-States’ communication and making sure we are trying to get ahead on issues or anything that may come up in the future,” Shelton said.

Check out a video of the project in progress, shared by El Paso Gridley CUSD 11 >>

Mid-States Wall Panels Erected for Industrial Project in Beloit

When it comes to industrial projects, Mid-States Concrete Industries’ precast products offer a positive impact to the construction process.

Our organization was proud to partner with Corporate Contractors Inc. (CCI) on the construction of a 500,000 square foot speculative industrial warehouse intended for a future tenant, owned by Phoenix Investors, a Milwaukee-based real estate agency.

For this Beloit project, located in the Gateway Business Park, Mid-States Concrete manufactured and installed more than 200 precast wall panels, and four pieces of hollowcore plank.

”We chose precast because it’s kind of the industry standard when it comes to these speculative [buildings],” said Aaron Combs, Project Manager for CCI. “… We chose Mid-States because of our longstanding partnership with Mid-States on these types of projects.”

While CCI considered both steel and tilt-up for the project, precast concrete offered the flexibility and time savings CCI needed for the timeline of the project. The wall panels were erected in roughly 12 days in July 2022.

”We started this project in March and turned it over to the owner in December,” Combs said. “Precast is able to meet our schedule, which provided savings to the client in the overall cost of the project.”

Combs added using precast helped the project run smoothly the whole way through the process. He said Mid-States knocked the shop drawings and the submittal process out of the park and simplified things. Because of that smooth process, CCI and Mid-States were able to spend time coordinating the jobsite up front, making it easier for the team to accept the panels in the field.

When it came to installation, Combs was impressed with the communication from the project management team at Mid-States, in terms of goals set each day and any impacts to those goals. He also commended the installation team for being on time every day, working hard, keeping a clean jobsite, and communicating well with the CCI team.

”At the end of the day, we’ve got a really good product and a happy client and it’s because of partners like you guys,” Combs said.

Mid-States Concrete Industries President Hagen Harker documented two visits to the jobsite in our Precast Chalk Talk series. Watch the videos to learn more about why precast concrete is a great choice for your next industrial project.

Precast Chalk Talk: Episode 36 >>

Precast Chalk Talk: Episode 37 >>

Committed to Quality

When it comes to ensuring the quality of the products manufactured by Mid-States Concrete Industries, our team has 11 dedicated team members focused entirely on Quality Control.

Our quality program is based on PCI Certification AC, C3 and B3-IL, as a PCI Certified Producer. We are also an S2 Certified Erector through PCI.

For example, Mid-States Concrete Industries completes a 300% inspection on our beams and columns, which includes a rebar cage inspection, pre-pour quality inspection, and post-pour quality inspection.

“PCI requires we check all those things, but not to the detail Mid-States does,” said Jeff Morris, Quality Manager.

“Mid-States does quality by the book and that book is our Quality System Manual, based off of the PCI MNL 116 & MNL 117, and ACI and ASTM standards,” added Mike Wolff, Vice President of Safety and Quality.

Mid-States also boasts a comprehensive internal training program for Quality Control, with the ultimate goal that all QC Inspectors are at least PCI Level II certified, and all foremen are PCI Level III certified. Currently, almost all inspectors are ACI field testing technician grade I.

For a beam, our 300% inspection begins in Cage Tie. At that stage, our Cage Tie team members refer to prints and cut the steel and bend all the stirrups in house. Then, they lay out the components and build the actual cage. Following that, a QC technician comes over and double checks all measurements, stirrups, etc. for accuracy against the engineered drawings. All mill certs are tracked and stored electronically.

Then, the cage gets transported over to our Wet Cast facility and put into the formwork. Prior to the cage being placed in the formwork, a QC technician checks the form for cleanliness, oil, elements, etc. to make sure everything is where it belongs.

From there, the QC pre-pour check takes over. The QC technician verifies placement in the form and all other embed materials, checking all measurements and tolerance, that all grout tubes are in the correct locations, and check every dimension.

“This is ensuring both the engineer and the customer are getting exactly what was designed,” Wolff said.

Then, we pour the concrete, which goes through a fresh concrete test every day, testing for air content of the concrete, spread/slump, temperature, and VSI. It is important to note that ahead of batching, all components of the mix design are verified to meet quality standards and a batch test is completed.

Our Quality Control team member remains present during pouring to make sure it is done per standards and samples are made as we are pouring. Then, we let the piece cure.

The next day, the product is stripped from the bed and taken out to the berms where a third QC technician inspects the finished product, verifies all dimensions, and makes sure it looks aesthetically pleasing. Any cleanup work that needs to be completed is handled by the detail crew, inspected again, and then marked ready to go for the customer.

When issues are found, Mid-States Concrete knows just what to do. The team holds weekly meetings to discuss any quality issues in the field and find ways to rectify these in the plant - before they ever make it to the jobsite. And on an annual basis, our Quality System Manual is updated and approved by PCI.

“The PCI Certification Program is the gold standard in my opinion,” Wolff said. “With PCI, we get two unannounced audits every year which entails a comprehensive audit of all our systems and our products. This audit process ensures we are following all quality processes correctly (all the time). Even when no one is watching.”