BIM and Precast: Where Physical and Digital Meet

By Debbie Sniderman

For centuries, designers have relied on two-dimensional physical representations of buildings to translate the ideas in their heads into actionable plans. When the advent of digital computing altered how nearly every profession on earth does its work, Building Information Modeling, more commonly known as BIM, allowed designers to bring those plans into the third dimension for the first time.

BIM software, however, is not only for creating 3-D models at the front end. It creates and stores information and shares it with other data-driven software, making it useful in not only design, but also production planning, manufacturing, quality control, storage, shipment and even tracking issues in the field. For precasters, BIM helps bring 3-D models together in software packages from different sources without the need to go back to 2-D drawings to match things up. It also makes it easy to exchange information with others trades.

During design

Rinaldo Pinchiroli, business development manager for CSG Engineering, says customers are pushing precasters in Italy to optimize production and designs to be competitive and requesting them to provide BIM solutions. Precasters are involved in the design stage, producing models for estimates to quote a job. They receive drawings from architects and clients, study solutions, create layouts and collaborate with multiple sub-trades involved in a project.

“In the estimation stage, BIM helps create preliminary drawings and layouts, including pieces, sizes, beams, columns, panels, and slabs for, say, a building project,” Pinchiroli said. “It automatically provides both the volume of concrete and the information about the complexity of the project (e.g. corbels, openings) to estimate the cost of materials and manpower properly.”

BIM also helps estimate structural elements, embeds and connections between pieces for the final design that aren’t included in the initial model.

“It’s faster to create final designs since the software creates connections automatically with structural calculations. It’s more precise, so you don’t risk missing anything from doing it manually,” he said. “The benefits of BIM for precast are different from when the industry changed from the drafting table to AutoCad. With BIM, the productivity benefits are in the design automation, after you’ve told the computer what rules to apply to automate the design.

“It’s a big step in productivity, but it’s not easy.”

Glen Hutchinson, North American precast account manager at Trimble, maker of Tekla Structures BIM software, said precasters who have taken the initiative to become BIM-enabled have enjoyed a market advantage.

“If precasters are brought on board as early as possible during the planning and design stages, they can cut the total project lifecycle down tremendously by using the BIM model as the single source to drive project data,” he said. “They won’t have to go back and forth with the typical RFI process.”

Photo courtesy of Trimble
Tekla Structures models allow detail work inside virtual buildings to identify potential problems early, evaluate alternative structural solutions and ensure constructability.

Powerful back-end benefits

Precasters typically use BIM to create final drawings and project models not only for the client, but also for manufacturing. As a result, benefits can include increased productivity, accurate quantity data and error reduction both in the plant during the production phase and on the jobsite during the erection phase.

Using a visual database is much more than a 3-D model used to create drawings. It can export materials, dates and project-driven data to any Enterprise Resource Planning system. Any type of precast product or project can be modeled and tracked through the system to improve internal productivity workflows as well as support external workflows benefitting all the project stakeholders. Status data can include dates, damage status, erection completed or even bidirectional site layout points.

On jobs where every piece is unique, precasters store information about each piece, which can save money during shipping and assists while planning where to store and pour items properly. When working on multiple jobs at once, knowing how to store pieces correctly is critical. BIM makes it easier to compare design and production costs by piece, by job and by line in addition to helping precasters plan both long term and daily.

Wells Concrete experiencing real benefits

Wells Concrete, headquartered in Albany, Minn., uses BIM internally to help produce its products used in places like commercial buildings, schools, stadiums, parking garages and even park restrooms. Jon Feist, director of drafting and outsource management, said when the company models a building, it becomes a huge source of information. Employees include every metal stud and link their Revit model to their accounting, ERP and sales software. It provides everything from preliminary forecast data to actual model data to their purchasing department.

Image courtesy of Wells Precast Concrete
Dashboards at Wells Precast Concrete show data on every member for every production job summarizing basic information fed directly from Revit models.

Wells Concrete uses BIM data for inventory relief and to keep track of consumption on the billing side of the business. On the planning side, it’s used to keep track of inventory moving around.

“Everyone in the company uses its data now, whether they know it or not,” he said. “Production personnel look at reports with cubic yards of concrete for the day’s pour generated from BIM. It ties into our current system and displays real-time data, so we get more up-to-date data and reduce the time people spend doing data input.

“Before, four departments all calculated the weight of every single member we produced manually. Now, no one needs to calculate it, Revit will provide it.”

At Wells, they are still discovering ways to use the data to make the company more efficient. With jobs constantly changing, BIM gives information in real time.

Tekla Structures and SolidWorks helping Dutchland produce tanks

Dutchland Inc. in Gap, Pa., needed a better way to produce the precast tank structures it designs, manufacturers and installs for the environmental industry. Its tanks and panels are generally 8.5 feet wide and need to weigh less than 44,000 pounds to ship. Its biggest design challenge is in the post-tensioning. Ducts go from panel-to-panel around circular tanks or corner-to-corner in rectangular tanks and all have to line up in the field.

Image courtesy of Dutchland, Inc.
Transparent view of a precast, post-tensioned concrete tank using Tekla Structures.

Chief Engineer Josh Allen said they wanted software to help make sure post-tensioning would line up across panel joints, and to produce more accurate production drawings for people in the plant and erection drawings for field personnel.

“The existing software could handle some parts of what we needed, but not everything,” he said. “We had to make workarounds to make the drawings look like what they needed in the field and on the floor.”

With its software from Tekla Structures, its designers are able to put all of the reinforcing steel in each piece into the model, something they couldn’t do before without bogging down the system. It lets the designers check interferences in 3-D and anticipate them before creating drawings. From the 3-D model, they create production drawings and export cut lists into Excel.

“It will save time creating reinforcing steel cut lists, and offer the ability for field personnel to pull up models on their field computers or tablets, to zoom in to specific project areas as needed,” Allen said. “Seeing the panels in 3-D on the shop floor or in the field will be a big help.”

Image courtesy of Finfrock DMC
XceleRAYtorAR projecting a flat slab on a form.

Allen suggests preparing for a significant investment in time to learn the software. Dutchland started in July 2017 and is close to completing its 18-month transition to learn, implement, test and train, all while maintaining its current workload.

“We should start doing real jobs using Tekla this May,” he said. “We want to use the powerful data extraction features in the software to be worth the investment and not simply use it as a second drafting tool. We see a long-term value in having all of the data in one place where different departments can access it.

“It will improve communication and it will be more real, less dependent on manual takeoffs onto spreadsheets or emails.”

Tindall’s progress with BIM solves big challenges

Mary Ann Griggas-Smith, corporate engineering manager at Tindall Corporation, headquartered in Spartanburg, S.C., said BIM benefits projects with multiple trades on-site. Her engineering group uses 3-D modeling to create production tickets from StructureWorks software. They apply this process to jobs like parking decks where the contractor may not have a BIM requirement.

Before creating models, Tindall’s engineering team had to convert 2-D drawings of standard plates and hardware into 3-D widgets. This required establishing drawing formats matching what their in-house shop was accustomed to using. Extensive upfront work was necessary to build custom pieces to fit into the prepackaged software, including writing routines to extract desired data. This learning curve often takes most companies by surprise. From job conception to approval, more time is required with BIM than 2-D drawings without a BIM requirement. But, Griggas-Smith says, the time and money savings are worth it.

The software makes it easier for Tindall to identify potential mistakes when using 3-D instead of evaluating the geometry from 2-D drawings. This is particularly helpful for complex geometries found in projects like stair towers.

“The biggest challenge is coordinating multiple trades at the initial stages of the planning and design process,” Griggas-Smith said. “This doesn’t always happen. The architect and big-ticket items like steel and precast are brought onboard early, before selecting mechanical and electrical subcontractors.

“Sometimes the contractors don’t have a BIM coordinator at the beginning of a project. But, all trades must be unified, and all work needs a common origin. Everyone must export with the same coordinate system so all models work together.”

By using BIM, Tindall can share exact item specifications produced by outside steel fabricators and input the data directly into CNC-controlled cutting machines.

Paperless tickets are the next step at Tindall. The company plans to use model data downstream where the benefits become clear.

“We’ve gained enough experience with the software and are pleased with the results,” Griggas-Smith said. “But, using the data only to create models misses the full value. We are starting to explore process improvements, the natural progression in the industry.

“People who use 3-D software longer tend to do more with it downstream than newer users.”

Automatically extracting data from an approved model eliminates manual counting and human error. The system knows what hardware is needed, including what plates and rebar to order. Tindall hopes to integrate directly from the model to tablets to send casting information directly to the bed without paper 2-D drawings.

Image courtesy of Finfrock DMC
XceleRAYtor laser projection on a form.

Griggas-Smith would also like to implement bar codes on every piece in the field.

“Ideally, an engineer or designer would monitor progress and review what has been erected each day,” she said. “We would love to arm erectors with tablets in the field. If dimensions are missing, the field personnel could access to the model and retrieve the information.

“Accessing substantial amounts of 3-D BIM data on the cloud can be slow so people are discouraged to use it. Computing power and internet speed at job sites often bottleneck usage.”

Image courtesy of Tindall.
Tindall uses BIM to quickly and easily ensure all loads leaving its facility are safe, stable and conform to DOT regulations.

Using BIM data in the future: What’s coming for precasters

There are new ways to use 3-D BIM model data to save even more time and effort. Wayne Maiuri, vice president of StructureWorks, mentions three of note for precasters.

Laser-assisted manufacturing is one option. Lasers can project features from the model directly onto forms so tape measures aren’t needed to set up product embeds or reinforcements, or perform QC processes. This will save time, eliminate paper and decrease errors. The lasers, coupled with the tablet-based, step-by-step 3-D manufacturing documentation, could save 30-70% of measurement time and effort.

In the future, employees could use BIM data with augmented- or mixed-reality devices such as the Microsoft HoloLens, projecting holograms onto the environment around a worker wearing head-mounted sets. The headsets would project everything in 3-D so workers could see rebar, mesh, strand or plates on a form.

QC techs performing inspections could approve and see the items turn green, or disapprove, take pictures of defects, specify a reason and turn the item yellow to review or address later without having to go back to a set of drawings.

“Technicians update screens when they complete their job and anyone can see who did what on any component,” Maiuri said. “When there’s a problem, it’s easier to find the person who touched it, request an engineering confirmation and see an image of a repair to verify defects have been resolved.”

Virtual reality headsets currently use BIM data as a marketing tool for owners to see how things look. In the future, precasters could use virtual reality with BIM data for training or as a collaboration tool in the pre-planning phase along with architects, general contractors and other sub-trades to see collisions in an immersive environment.

BIM today

For now, Griggas-Smith says BIM is still in its infancy in a lot of ways. However, she feels there is a shift occurring in the precast industry as more companies are realizing the benefits of using the software.

“Going from pencil and paper to drawing lines in AutoCad seemed cumbersome at the time,” she said. “But when you become more comfortable with a tool, the method becomes much faster. Our group of 20 designers are enthusiastic about the software and improved processes.”

Debbie Sniderman is an engineer and CEO of VI Ventures LLC, an engineering consulting company.