3D Modeling Software Improves Concrete Construction Efficiency
Companies across North America call on Barton Malow to build some of the most technically challenging projects. Headquartered in Southfield, Michigan, the $1 billion national construction services company delivers projects through a variety of methods to build trust and ensure safety, quality and productivity. With their extensive self-perform capability coupled with their use of innovative technology like Building Information Modeling (BIM), Barton Malow is one of the top performing contractors in education, energy, federal, healthcare, industrial and manufacturing and special event facilities.
Founded in 1924, Barton Malow used 2D drawings to design its projects until 2008, when it began embracing BIM. Fast-forward four years to 2012, when a few experienced Barton Malow BIM users in the resteel department decided to investigate whether Tekla Structures—long used as a construction management tool at Barton Malow—would offer the team more capabilities, especially for resteel and concrete detailing. After a month-long trial, the group adopted Tekla Structures.
“After working with Tekla Structures for a month, we decided to move forward with it and haven’t looked back,” said Matt Hedke, Barton Malow’s Resteel Fabrication Manager. “It didn’t take long to see the benefits for Barton Malow and our clients. Tekla is definitely a construction BIM solution that’s geared toward the contractor and the company prides themselves on understanding what we do. No other software provider is as advanced as Tekla, especially with cast-in-place concrete and rebar modeling. We knew there would be a learning curve, but we embraced it because we knew the end result was where were wanted to be.”
In less than a year’s time, the Barton Malow team put Tekla Structures to the test and is already seeing the benefits, including impressive efficiency gains upwards of 15 percent. The team is learning to customize Tekla. For example, they’ve developed templates to create automated assembly tags, which provide instructions on how to pre-tie a cage to improve rebar placement efficiency. What’s more, Tekla’s Rebar Release Manager helps the Barton Malow team keep track of each release of rebar and associate it with each concrete pour.
“We’re seeing incredible results and we’re just getting started,” said Hedke, “There is a tremendous amount of customization this software allows us to do. The Tekla support team has been extremely supportive and responsive in helping Barton Malow understand how to get the most out of the software and to become proficient in using it.”
Barton Malow finds the tools in Tekla’s software for scheduling columns and detailing slabs, base plates and stirrups particularly effective for improving efficiencies by enabling the team to rapidly add detail to their drawings.
“Before Tekla, we simply didn’t have the time or the tools to easily add this depth of detail,” said Hedke. “Our focus was on detailing the rebar rather than the various components of the concrete object. Tekla allows us to see in 3D how everything will fit together and if we will run into clashes or interferences.”
“Since we self-perform many different trades and disciplines, it just makes sense that we should know exactly how things like embedded iron and anchor bolts fit with the rebar before the construction phase,” said Hedke. “We also share the Tekla 3D model with the field project manager and crews, so they have an accurate reference for their work. The operations personnel are using this information to plan pours.”
These capabilities have become a core part of Barton Malow’s self-perform approach.
If a 3D model already exists, the Barton Malow team imports it into Tekla to use as a reference to add the concrete and rebar. Tekla supports a wide variety of file formats, allowing the team to use and share the model with internal and external engineers, as well as trades, and allows the project manager to combine various models together for a complete view.
“Tekla truly enables collaboration during the design phase and on the job site,” said Hedke.
The model is not just a tool for drawings and coordination though. To gain the full potential of the software, Barton Malow tied the model to their fabrication software, Shear97.
“We were able to model bars, create drawings and send all the information directly to our fabrication system,” said Hedke. “If the model is correct we know the drawings are as well and we know we’re fabricating exactly and only what is needed for the job”
Tekla at Work
Karn/Weadock Power Plant
Barton Malow won the contract to design and construct two cast-in-place concrete silos and equipment and building foundations totaling over 10,000 yards of concrete to be placed at Consumers Energy’s Karn/Weadock Power Plant in Essexville, Michigan. This contract was part of a larger project to install air quality control equipment to help the company meet future environmental regulations. The design for the 110’x 46’ silos was particularly complex and the timeframe for completing the project was aggressive.
“Barton Malow’s use of Tekla allowed them to efficiently coordinate structure openings and embedments with equipment vendors and align with the unique requirements of the silos at our site,” said Corietta Meeks, Consumers Energy Construction Manager. “This was crucial in executing the work quickly within a small footprint.”
Each silo has 10 lifts, a lower composite slab, a roof composite slab and a four-foot thick structural slab, all cast in place. To complicate matters, each silo has as many as 40 different openings. Some openings are round; others are square and many are placed at challenging angles. In addition, sleeves of varying diameters bisect the silos either perpendicular to the wall or at a 45 degree angle, and the rebar splices are staggered.
“Once we modeled the silos in Tekla, we quickly discovered the current design would have been extremely difficult to fabricate and install,” Doug Demongey, Barton Malow’s re-steel detailer. “We took snapshots of the Tekla 3D model—instead of drawing a sketch or typing out a multi-paragraph explanation—to illustrate the conflicts between the openings, sleeves and rebar. The engineer immediately saw the problem, which allowed us to work with him to find a solution that would benefit both parties. If I had done this in 2D, I might not have caught it.”
“For visualization, you just can’t beat a Tekla model,” said Demongey. “If you show the design engineer a 3D image of an interaction issue accompanied by a brief explanation, he sees exactly what the problem is. I can’t stress how important that is to overall job efficiency.”
After Demongey modeled the concrete and rebar, he published the model to Tekla BIMsight, so that the field staff could readily access it. The field project manager used the model to order the correct amount of concrete for each pour from the job site.
“We saw huge benefits using Tekla, especially how the openings and sleeves interacted with our steel,” said Hedke. “With all of the variables in the silo design, I’m not sure we would have been able to do it as accurately without it.”
DTE Echo Wind Farm Project
Barton Malow also saw the benefit of using Tekla Structures to design foundations for the Detroit Edison Energy (DTE) Echo Wind Farm, a renewable energy source serving several counties in Michigan’s “Thumb” region. Once the Barton Malow engineering team completed the design for the two types of wind turbine foundations, Hedke’s team modeled the foundation rebar, concrete and anchor bolts in Tekla Structures.
The design called for each foundation to be reinforced by 144 anchor bolts placed four inches apart and arranged in two concentric circles with the top mat reinforcing bisecting each anchor bolt. It was critical to identify any potential interference to ensure the spacing would work in practice as well as it did on the engineer’s design. The Tekla model revealed several places where interferences occurred between the anchor bolts and top mat reinforcing.
“After the rebar clashes were corrected, we could rapidly generate accurate placing drawings,” said Demongey. “We also specified how to bundle the steel, so that it would be easy to distribute at the job site.”
Each placing crew was given a specific drawing depicting their area of work and showing exact spacing and sequencing information. This information was easily extracted from the Tekla model.
“Because the models were so accurate, we were able to take the dimensions from the model to show where each wind turbine would fit on the jobsite,” said Hedke. “The Tekla model showed us the conflicts, which we corrected early on so that by the time we got to the construction phase, it was very organized, very well put together.”
In addition to designing the foundations, the job called for Barton Malow to put in roads to each wind turbine site, dig the foundations, place the rebar, erect and set anchor bolt cages, form the foundations, place and finish the foundations and and erect the turbines – all on an extremely tight construction schedule. Two foundations needed to be poured each day to meet the turbine erection schedule.
“With a compressed schedule and a challenging site, accuracy and a clear understanding of what you’re doing becomes critical,” said Hedke. “After the first foundation went in, we got feedback from the field saying it couldn’t have gone any better. After that, it was just a matter duplicating the process. Taking the time to model the concrete and rebar detail in Tekla really paid off on the backend to meet our installation schedule.”
Even though the Barton Malow team is still new to Tekla, they’re already seeing a 10-15 percent reduction in man-hours per project just for rebar detailing. This efficiency gain is reinvested in the job to incorporate more information into the model.
“I predict that we will see our efficiency gains increase even more as we become more proficient with Tekla,” said Hedke.
Chuck Binkowski, Vice President of Barton Malow, credits Tekla with improving efficiencies in the firm’s self-perform work and helping it win more business.
“Barton Malow has a long-term goal of doubling our efficiency by 2024—our 100-year anniversary,” said Binkowski. “It’s clear to me that partnering with Tekla advances our leadership position in the industry and will be instrumental in helping us achieve our efficiency goals. Our customers expect this of us and that’s what we want to deliver.”