C+S July 2020 Vol. 6 Issue 7 (web)



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THE COVER First Class Data– story on page 10

CHANNELS ENVIRONMENTAL + SUSTAINABILITY 14 Here, There, and Anywhere 16 Topping off LEED Certification with a Green Roof 17 The Post-Covid-19 Sustainability Chase STRUCTURES + BUILDINGS 19 Tunneling to Connect Fort Worth 21 U.S. Army Corps of Engineers comes to the Aid of Hospitals 23 Transforming Communities Through Brownfields Redevelopment 25 Modified Ransome Shark Tooth Splitter Helps Contractor Save Hawaiian Bridge 27 Veterans Memorial Bridge TRANSPORTATION + INFRASTRUCTURE 31 How to Head Off Problems and Get the Most Efficiency Out of an Electric Fleet Conversion 33 Helping Public Transit Agencies Move from the Current Crisis to a Better Normal 35 Pavement Recycling Systems Invests in New Rapidmix 400CW for New RCC Projects after Successful Lease Trial WATER + STORMWATER 36 The Connection Between Cooling Towers and Legionella Transmission: How Can We Effectively Reduce the Risk? BUSINESS NEWS 38 COVID-19 & the New Normal for the A/E/C Industry SOFTWARE + TECH 41 “Connected Highway” Demonstrator Shows How Easy It Can Be to Federate IoT Data in Infrastructure Digital Twins 43 Cybersecurity for AEC Firms During COVID 19 Pandemic UNMANNED SYSTEMS 44 Remote Control: Drones Become Mission Critical Engineering Tool SURVEYING 46 Third Track’s a Charm departments 8 Events 48 Reader Index Columns 5 From The Publisher: Driving Change Chad Clinehens 6 Looking Back, Moving Forward: Building the Alaska Highway Luke Carothers




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VOLUME 6 ISSUE 7 csengineermag.com

publisher Chad Clinehens, P.E. | 479.856.6097 | cclinehens@zweiggroup.com media director Christy Zweig | 479.445.7564 | czweig@zweiggroup.com Production & circulation manager Anna Finley | 479.435.6850 | afinley@zweiggroup.com ART director Maisie Johnson | 417.572.4561 | mjohnson@zweiggroup.com Editor Luke Carothers | lcarothers@zweiggroup.com

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Civil + Structural Engineer (ISSN 23726717) is published monthly by Zweig Group, 1200 North College Avenue, Fayetteville, AR 72703. Telephone: 800.466.6275. Copyright© 2020, Zweig Group. Articles not be reproduced in whole or in part without the written permission of the publisher. Opinions expressed in this publication are not necessarily those of Zweig Group. Unsolicited manuscripts will not be returned unless accompanied by a stamped, self-addressed envelope. Subscriptions: Annual digital subscription is free. To subscribe or update your subscription information, please visit our website www.csengineermag.com/ subscribe/ or call 800.466.6275.

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july 2020

from the publisher

We live in a world of change, especially now. COVID-19 forced all of us into a dramatic state of change, almost overnight, and may have pushed a fragile economy over the cliff. Three months and counting and much of our staff are still working from home. Just when we thought things were going to open back up, some areas are re-instating restrictions because of surges in cases. Airports and hotels are empty, car sales are dead, and restaurants are closing up for good. We all seem to be living day-by-day, not know what the next month looks like. Fortunately, the overall picture for the AEC space looks far better than it does for hospitality, entertainment, and dining. This does not mean, however, we can relax. On the contrary, it’s apparent that if there was ever a time to reevaluate what you’re doing, it’s right now. Everything is different. It’s getting ugly, and it will probably get uglier as COVID-19 is not going away anytime soon. Here are some of the things you can do to stay strong in a time of crisis: bTune up financial reporting and forecasting systems— In a time of crisis, you need to be able to get up-to-the-minute information that shows where the bleeding is so you can act quickly. Acting quickly on old information can waste a lot of money. Meet with your leadership team more often, so you can make real-time decisions. Leadership and management in a time of crisis is put to the ultimate test. I think we can all agree that this is the greatest test of our careers. Take a hard look at the markets you serve—I suspect airports will still be a good market, but there will be much less air-side work (runways, taxiways, etc.) in the short-term and much more on the land side (terminals, baggage handling, security) because of COVID-19’s changes to how we move people to and from the planes. There will have to be more roadway work, especially if air travel is greatly reduced, and this could be greatly enhanced with a stimulus bill. Currently, there are historic demands for RVs which is indicative of a shift in travel and vacation habits. Could it be we return back to an era of nostalgia that where road trips, outdoor motor lodges, and roadside dairyettes return as the norm? Now is the time to get out of this day- to-day survival mode and look ahead as to how a longer-term COVID-19 world affects design and construction in the markets you serve. Evolve your marketing messaging—This is not time for the standard boilerplate language you’ve been using for years, or even decades. Now is the time for new and current language that reflects this extraordinary world that everyone is living in. Unlike previous recessions that hit certain sectors far worse than others, COVID-19 is something that is affecting everyone in some form or another. Consider your altering your messaging to serve a greater purpose and to bring empathy to the conversation. There is a lot going on for your clients and now is the time you can develop the best relationships your firm has ever known. Clients change, markets change, economies change, service offerings change—change is certain, especially in this time of COVID. Driving this change effectively is something that every firm leader must learn to do to enable their firms to sustain their success in the ever- uncertain future. Now is not the time to be along for the ride! Consider both the temporary and permanent change your business needs to embrace – from the marketing message, to the market demand, to the project design, to the metrics – your firm must identify the issues that threaten it and how best to evolve to conquer them. We’ve likely got a rough road ahead, but with aggressive management, willingness to change, and a resilient spirit, we will weather this major storm and come out stronger than ever.

Driving change

CHAD CLINEHENS, P.E., is Zweig Group’s president and CEO. Contact him at cclinehens@zweiggroup.com.


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Looking back, moving forward

On February 11, 1942 President Roosevelt approved a plan that had been in motion since at least six years prior: the Alaska Highway. After the U.S. joined World War II on the side of the Allies, there was a sudden need to reinforce defensive installations along the WesternAlaskan coast against attacks from the Japanese Navy. The territory covered by the highway was considered inhospitable to many and featured a daunting stretch that traversed the width of the Canadian wilderness. The engineers faced down an endless wilderness of sub-arctic forests, swampy fields, and snowy tundra. On top of this, the project had a very short window. The highway had to be completed over the course of the Spring and Summer of 1942 lest the harsh Northern snows impede all progress. To compound these problems, the Japanese had begun to attack and invade American defensive positions along the Aleutian Islands on Alaska’s Western coast. The United States needed these bases secure and sufficiently provisioned if they were to continue shipping and patrolling the Northwest coast. Such a massive undertaking required manpower and technological prowess unlike any transportation and infrastructure project to that point in the history of the United States save the construction of the Panama Canal. With most of the U.S. Army Corps of Engineers helping allied forces in the Pacific, President Roosevelt made the decision to eschew tradition; he sent three regiments of Black engineers—the 93rd, 95th, and 97th Engineer General Service Regiments— to complete the project along with four regiments of white engineers. The three Black regiments were given the task of starting on the Northern end of the project and working south to meet up with the white regiments. Beginning in the late Alaskan winter, these engineers had to first fight through the harsh cold. On top of that, when the snows finally subsided, the regiments had to deal with stifling humidity and bloodthirsty mosquitos. At the time of the highway’s construction, the United States Army was strictly segregated, and there was a strange law that forbade Black regiments from being deployed to anywhere but warm climates. These engineers had to face challenges that their colleagues at the time could never have imagined, on top of dangerous terrain they were working on. Along with the prevalence of Jim Crow laws and racist sentiments amongst the units they labored alongside, these three regiments of engineers had to deal with obstacles created by their own command chain. Many white officers believed the regiments unfit for this work, and, as such, sought to passively and actively hinder their progress by providing them with less support and resources. In one famous example, the 95th Engineer Regiment, which was comprised solely of Black engineers, was forced to tackle the same sub-artic forests and jagged peaks with nothing but hand tools. The equipment was available, and the 95th was extremely experienced in using it, but it was instead given to the all-white 35th regiment, who had far less experience operating it. Despite the odds stacked against them, these three regiments chipped away at their task for nearly a year. In less than eight months, the project was nearly complete. On September 24th, 1942, the two ends of the highway met in what is known as Contact Creek. Although minor work would continue on the highway for years to come, this is largely celebrated as the completion of the highway and there was a ceremony the next month. It was memorialized in United States newspapers with a clear image that stuck in the minds of many Americans at the time—a Black engineer shaking hands with his white colleague, grinning. The hardships faced by the Black engineers working on the Alaska highway should not be forgotten. Their ability to rise above circumstance and elevate the world around them had an indelible effect on not only the country, but the continent as a whole. Although their efforts have been memorialized in structures such as the Black Veteran’s Memorial Bridge Fairbanks, Alaska, it is important to keep these men in our hearts; they are the paragon of bravery, work ethic, and professionalism; their legacy

Building the Alaska Highway Luke Carothers

LUKE CAROTHERS is the Editor for Civil + Structural Engineer Media. If you want us to cover your project or want to feature your own article, he can be reached at lcarothers@zweiggroup.com.



july 2020

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Tickets are now available for the ACI Excellence in Concrete Construction Awards Gala. This premier event will celebrate the concrete industry’s most prestigious and innovative projects from around the globe.

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events + virtual Events

July 2020

October 2020

automated vehicles symposium starting july 14 – virtual

AUVSI Xponential rescheduled: october 6-8 – dallas, tx

The Automated Vehicles Symposium (AVS) brings together more than 1,500 professionals — leaders, academia, engineers, policymakers, researchers and solution providers to learn, share and connect on the evolving AV industry. Come together to learn more on regulations reform, industry roadblocks and foresights into the next steps in deployment. Through interactive breakout sessions, a thought- provoking plenary schedule, groundbreaking research posters, and the Enterprise Solutions Series, this Symposium is the place to experience how the industry is driving forward. https://www.automatedvehiclessymposium.org september 2020 AUVSI Unmanned Systems—Defense. Protection. Security. (USDPS) is the only event focused on equipping our armed services and civil protection agencies with the unmanned tools they need to meet today’s threats while preparing for tomorrow’s opportunities. You’ll join military officials from across all branches, federal security personnel, and industry leaders to understand the latest programs of record, navigate procurement processes and explore opportunities to do business with federal agencies. https://www.thedefenseshow.org auvsi unmanned systems- defense protection securtiy september 8-10 – virtual This one-day event is open to all and for anyone interested in learning more about how to solve the AEC industry’s top challenge: recruitment and retention. The ElevateHER symposium will gather together leaders in the AEC industry, Zweig Group’s ElevateHER 2020 Cohort members, and speakers on topics related to hiring, retaining valuable employees, and fostering a diverse and equitable workplace. https://shop.zweiggroup.com/collections/conference/products/ elevateher-symposium?variant=31530063265864 The Elevate AEC Conference & Awards Gala (formerly the Hot Firm & A/E Industry Awards Conference) is the AEC industry’s premiere experience to connect global leaders, solve industry issues, present next practices, and celebrate the most successful firms in the built environment. https://shop.zweiggroup.com/collections/conference/products/2020- elevate-aec-conference?variant=30365800988707 elevateher symposium september 30 – denver, co elevate aec conference september 30-October 2 – denver, co

AUVSI XPONENTIAL 2020 is the global stage for everything unmanned — from state-of-the-art propulsion technology, sensors, energy storage and UAS mitigation solutions to what’s coming over the horizon in AI, 5G, edge computing, and more. As the largest, most significant event for the unmanned systems industry, you’ll find your edge as you explore the latest technology innovations, develop new perspectives as you hear from industry luminaries, and cultivate creativity at special networking events where you will meet some of the most influential leaders in the unmanned and autonomous space. https://www.xponential.org/xponential2020/public/enter.aspx This one-day training course covers the critical focus areas every AEC Industry project manager should be familiar with and is presented in lecture, tutorial, and case study workshop sessions. Attendees will leave armed with a comprehensive understanding of the characteristics, skills, and techniques successful project managers must have to flourish in their role. Project Management for AEC Professionals october 14 – minneapolis, mn https://shop.zweiggroup.com/collections/seminars/products/ excellence-in-project-management?variant=30890364796963 Learn the Language of Business: Financial Management october 20 – dallas, tx Solid financial management is crucial to the success of any company, and firms in the AEC industry are no exception. This course provides an overview of business financial management – specifically tailored to our industry – to help firm leaders make informed decisions. Topics include: interpreting financial statements; key performance metrics; benchmarking and predictive cash flow management; and how strategic decisions drive the value of the firm. https://shop.zweiggroup.com/collections/events/products/financial- management-for-non-financial-managers?variant=15425604845603

design-build conference and expo october 28-30 – national harbor, md

Design-Builders in the Water/Wastewater and Transportation sectors will be the focus of two dedicated tracks of education targeting the unique needs of each sector. https://dbia.org/conferences/design-build-conference-expo/

Leadership skills for AEC Professionals rescheduled: october 29-30 – dallas, tx

Practical leadership skills are vital to the health and success of every company in any industry. Effective leaders motivate their teams to achieve exceptional results, inspire others to be better than they thought possible, and create an environment where their team is focused and working towards a common vision. Zweig Group’s team of management experts – who have extensive experience working with



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AEC firms providing solutions to the challenges facing AEC firms today – deliver practical solutions that technical professionals can put to work immediately to lead their firms to success. https://shop.zweiggroup.com/collections/events/products/leadership- skills-for-aec-professionals?variant=30889848569891 virtual This is a 6 week program of 1 hour each week live zoom meetings with our seminar instructors. These meetings will be a mix of presentations, discussions, and open ended Q&A sessions, with the ability to continue the discussion via discussion forum from week to week. This will be the same great content that is taught during our in-person Project Management for AEC Professionals seminar. This program will have a limit of 30 participants so each participant will have time to ask questions and get the same cohort feel as an in-person seminar does. https://zweiggroup.myshopify.com/collections/webinars/products/ project-management-for-aec-professionals-virtual-seminar-starting- july-14-2020?variant=34600145813655 Project Management for AEC Professionals starting july 14 – 6 pdh/lu Elevating Doer-Sellers: Business Development for AEC Professionals starting august 5 – 6 pdh/lu Elevating Doer-Sellers: Business Development for AEC Professionals is specifically developed to help design and technical professionals in architecture, engineering, planning, and environmental firms become more comfortable managing clients and promoting the firm and its services. Led by two retired and current CEOs with extensive experience from the design desk to the board room, this one-of-a- kind seminar presents business development techniques proven to drive real growth and value in your AEC firm. Beyond the buzzword heavy, ra-ra approach of other business development and sales training seminars, Elevating Doer-Sellers: Intensive 2-Day Workshop focuses on what really works in today’s AEC firm utilizing practical and proven techniques that resonate across the organizational chart. https://shop.zweiggroup.com/collections/webinars/products/elevating- doer-sellers-business-development-for-aec-professionals-virtual- seminar-starting-august-5-2020?variant=34614078701719 Solid financial management is crucial to the success of any company, and firms in the AEC industry are no exception. This short course provides an overview of business financial management – specifically tailored to our industry – to help firm leaders make informed decisions that drive results. Topics include: interpreting financial statements; key performance metrics; benchmarking and project cash flow management. https://shop.zweiggroup.com/collections/webinars/products/copy-of- recruitment-retention-webinar?variant=31805139320904 Driving Financial Results Webinar 1 pdh

Recruitment & Retention Webinar .5 pdh

Zweig Group's research shows that recruiting and retention are the #1 challenges AEC firms have faced in the last few years. This webinar discusses current data from exclusive industry survey results that can be used to effectively develop your firm's recruitment and retention strategy in any type of job market. https://shop.zweiggroup.com/collections/webinars/products/ recruiting-retention?variant=31792090054728 The way we work, do business, and interact is constantly evolving and changing. Leaders are the first we look to when we need to adopt a change or understand how change affects us personally. You and your team must understand how to lead and adapt to an ever-changing environment. This seminar is designed to help you proactively lead your firm or team through change. You’ll learn what makes change challenging, several models and systems to lead change efforts, you’ll learn how to define and accept your role in change and gain practical frameworks for becoming an effective change leader. https://shop.zweiggroup.com/collections/webinars/products/change- management-webinar?variant=31811496476744 Change Management Webinar 1 pdh Understanding Key Financial Statistics in the AEC Industry .5 pdh Financial statistics and ratios are crucial to assessing your firm’s financial health. Zweig Group’s Financial Performance Report of AEC Firms helps firms compare their performance against industry norms, comparable firms, and specific performance categories. This webinar will highlight several key financial statistics, how they are calculated, and what the industry trends for each measure look like over the last five years. https://zweiggroup.myshopify.com/collections/webinars/products/ understanding-key-financial-statistics-in-the-aec-industry- webinar?variant=31816904441928

Ownership Transition in the AEC Industry 1 pdh

Zweig Group examines the ever-complex environment of ownership transition in anAEC firm. The presentation covers a range of topics, giving


july 2020



First-Class Data A small, woman-owned firm is landing big survey contracts at a top ten US airport By Mary Jo Wagner

If the Charlotte Douglas International Airport (CLT) offered frequent contractor points, the professional land surveyors at CES Group Engi- neers would likely be triple platinum members. Since late 2015, the engineering and survey company’s crews have been at the facility nearly every day in support of CLT’s roughly $3.1 billion program to renovate its concourses and expand its roadways, curb front, airfield, and terminal. Being an integral part of such a high- profile project is testament to how far this company has grown from the modest, residential lot surveys it was providing after launching its surveying services eight years ago. “We’ve experienced tremendous growth in a notably short amount of time because we fulfill a significant need for professional land survey- ing services, an expertise that’s been in short supply in this region since the 2008 recession,” says Judy Heleine, owner of CES, based in Den- ver, N.C., about 25 miles northeast of Charlotte. “Our surveyors and engineers are out in the field nearly every day and they get noticed for the quality work they do. That experience, knowledge, responsiveness, and enabling technology allows us to deliver the required precision on one project and helps seal the deal on the next. It’s a winning formula that has earned us a place on some of the highest profile projects in the region.” Being early adopters of advanced survey and geomatics technologies has also enabled CES to expand its breadth of services and pursue sub- stantial contract opportunities with more confidence. “We invest heavily in varied technology that allows our licensed land surveyors and field crews to tackle any surveying job out there,” says Kent Hudson, PLS and CES’ geomatics division manager. “Each new piece of equipment builds our expertise, which helps us deliver speci- fied results on time and on budget, heightening our profile and enabling us to secure immense projects like CLT.” Indeed, equipped with a pool of modern survey instruments and newly acquired scanning technology, CES survey crews have been providing first class data to help engineers build CLT’s final destination. Destination CLT CLT is the 10th busiest passenger airport in the United States, ranking higher than some of the country’s biggest names: Orlando, Miami, and Houston. In one decade, it flew from the 18th busiest airport to the 11th in 2016, landing in the top ten last year by welcoming 46.4 million domestic travelers and 3.2 million international passengers through its 114 gates and five concourses. Such growth has been putting CLT on a collision course with overcapacity.

The city of Charlotte, North Carolina.

With all indicators showing increased passenger demands, airport ex- ecutives developed “Destination CLT,” a master blueprint that defines the construction and renovations it needs to ensure it has the capacity to handle future growth through 2035. Given CES’ proven performance on previous design and construction surveying projects at the airport, and its knowledge of the facility, multiple CLT prime consultants and contractors chose the company to serve as the primary survey provider for more than 24 individual projects. Since construction work began in 2015, CES survey crews have been on the ground floor of the majority of the anchor projects designated in Destination CLT, including the $200 million expansion of Concourse A, the first completed project in the initiative, which added nine gates, constructed a new ramp and taxi lanes for the new gates and modernized its amenities. Assisted by their Trimble S7 robotic total stations, Trimble DiNi Digi- tal Levels and TSC3 and TSC7 data collectors, CES field teams have been providing all aspects of construction staking. “For all of these projects, we’ve had to ensure that all of our horizontal and vertical points are accurate to within 0.01 feet,” says Hudson.



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opened in April 2019, marking the completion of Phase 2 of the $50 million initiative. The final stage of the project is scheduled to finish in the fall of 2019. Initial construction began in November 2015 and CES crews were on site from day one. Every day for three years, field teams were using their survey equipment for installing control points, and staking out curbs, piers, girders, columns, as-builts, and bridge bents, which are structural elements used to support girders. They also used their tech- nology to locate existing storm and sewer infrastructure and stake out new construction points for rerouting and replacing those systems. “We had extremely tight tolerances to ensure all the pre-fabricated steel beams fit correctly and were at the correct height and horizontal plane dictated by the design,” says Hudson. “All of our measurements had to be exact.” In the latter stage of Phase 2, CES was asked to perform as-built surveys of the support columns for the elevated roadways and bridge ramps. As they had just acquired an SX10, the timing proved opportune. CES had been doing column as-builts with their traditional equipment and it was painstaking. To capture the circular columns, crews needed to measure the circumference, shoot multiple points around the col- umn, bring that data back to the office, and then calculate the “best fit circle” to indicate the column center. Using the scanning function of the SX10 allowed them to capture the entire column at once. “In addition to the time-consuming process, traditional techniques require a prism, which can introduce some error because of its thick- ness,” says Hudson. “So you have to perform many calculations and checks to ensure you’re precise. With scanning, you get the actual surface so it’s easy to pinpoint the column center.” With the SX10 available, a field team opted to scan seven remaining bridge columns––the instrument’s debut project at CLT. After re-establishing site control––given the confined, active work site, they had to verify control every day––the two-person crew set the

“That’s not easy to consistently maintain when you have such a cha- otic, machine-heavy and sometimes cramped work site. But despite the challenging and unexpected conditions, we’ve been able to stay on spec every day.” And since the summer of 2018, they have been able to extend the breadth and detail of their data through the addition of Trimble’s SX10, a scanning total station that combines surveying, imaging and scan- ning. That functionality has proved particularly useful for two other massive airport projects: the Elevated Roadway (EVR) and the South- Crossfield Taxiway (SCT). “The SX10 has become instrumental on CLT projects,” says Hudson. “It’s not only giving us the flexibility, speed, mobility, precision, and safety we need, it’s reinventing some of our historically tradition- al survey approaches and creating new business opportunities.” Elevating efficiency An extensive, four-year undertaking, CLT’s EVR project is widening the existing four-lane terminal approach road to 16 lanes to create more badly needed space for vehicle drop offs and pickups. Five new up- per lanes of the EVR and four temporary passenger walkways were

The new and improved Concourse A at Charlotte Douglas International Airport (CLT), the first completed project under the Destination CLT initiative.


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Five new upper lanes of the CLT’s Elevated Roadway and Terminal Curb Front opened on April 3, allowing drivers a more expedient Airport entry.

Based on the success of their first experience with the instrument, it wasn’t long before Hudson tapped it to resolve another challenge at CLT. A good surprise In January 2019, one of the primary design-consultants on CLT needed survey support for CLT’s ambitious South-Crossfield Taxiway (SCT) project, a new 4,000-foot-long taxiway, along with a bridge, that will connect the central and east side of the airfield. CES worked with the consultant company on previous projects for the City of Charlotte, in which they produced cost effective, high quality deliverables on time. Based on that success, the company selected CES for the SCT project. CES’ field crews were tasked to create a topographic survey of the entire site, which consists of dense, wooded areas; low vegetation ar- eas; flat, open taxiways and runways; and elevated retaining walls and ramps. As part of that survey, they needed to locate and map critical utilities, taxiways, runways and ramps. Such a varied landscape re- quired multiple technologies and approaches. CES crew chief, with properly secured safety harness, completing as-built survey of elevated roadway girders, using Trimble S7 Robotic Total Station and TSC3 Data Collector.

scanning total station on a control point and scanned the first column 100 ft away. They performed that routine three more times and in less than three hours, they captured 3D, 360-degree views of each of the seven columns at an accuracy of 0.01 ft. They saved the data on their TSC7 controller using Trimble Access field software, which combines optical, scanning, and GNSS data plus images in the same job. “Scanning eliminated the need for setting traditional targets and pro- vided a safer working environment for our crew,” says Hudson. “And we captured substantially more data––millions of data points––in half the time it takes with the conventional methods.” Back in the office, Hudson input the SX10 point cloud into Trimble Business Center (TBC) software for processing and quality control. He then exported the 3D data intoAutoCAD to produce a final drawing showing the column centerline locations. Per the client’s request, they delivered the drawing as a PDF. CLT elevated roadway surface under construction, between the terminal building (left) and parking garage (right)



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300 feet from the instrument. In 10 scanning set ups, the crew captured the entire 40 acres in a single seven-hour shift. “I didn’t think I’d use the scanning functionality on a huge, flat surface so I wasn’t sure how it would perform, particularly in low light,” says Hudson. “I went to the site expecting it would be a three-night job, and I was shocked that we got it all in one night. Our dealer, Duncan Parnell, had assured me that darkness wouldn’t be a problem, and they were right. I not only acquired millions of 3D points that clearly show all the concrete seams and subtle grade variations, I captured substan- tially more data in nearly 13 percent of the time.” An additional efficiency benefit came from the “big picture” screen of the TSC7 and the integrated survey workflow provided through Trimble Access, which enabled crews to seamlessly manage the data from myriad project tasks and sync data between field and office in real time. “The large controller screen makes it really easy to see in any environ- ment like bright sun, overcast, in the middle of the night and even wear- ing polarized sunglasses,” says Hudson. “That allows us to quickly set up new jobs and move between jobs. And with Trimble Access we can transfer data between the office and field in real time and check emails so it’s like having your office with you.” Back in the office, Hudson processed the point cloud using TBC software and its automated extraction tools to remove any extraneous features such as parked airplanes. After cleaning the data, he created a 3D topographic model of the 40-acre concrete apron and exported it into AutoCAD to produce a final 3D surface. Two days after capturing the data, CES delivered the topographic survey to their client. Since finishing that survey, CES teams have been back on the SCT site with their S7 total stations to collect the locations of all the sewer and storm systems across the 300 acres. Work on the SCT project will continue through 2022. With the company involved in 16 active projects at the airport, Hudson cannot readily predict when the SX10 scanning functionality will be used again––they use it every day as a total station––but he says it’s only a matter of time. “Since purchasing the SX10, I’m using it in on projects I never thought I would, like scanning features at busy road intersections and large- diameter water main projects,” says Hudson. “Its versatility, the ability to scan and survey in one instrument, its ease of use and its speed save us so much time in the field. And on such massive projects like CLT, we need that. It does not sit idle.” Between Destination CLT and other on-going projects, CES won’t be sitting idle, either––it just opened its third office in Columbia, S.C. With a docket that looks as full as CLT’s departure board, those phan- tom frequent-contractor points probably wouldn’t get used anyway.

However, because this site is located within CLT’s airfield, CES was required to perform their work overnight to avoid disrupting airport operations and to ensure their safety and the safety of airport staff and airline personnel. They set control using a number of Trimble R8s GNSS receivers, occupying each control point multiple times and then calculating the averaged coordinates for each point. They then ran a closed traverse loop using the S7 for horizontal control and the DiNi level for verti- cal control to within 0.01 ft. With control established, three different survey crews used multiple S7 total stations and TSC7 data collectors to collect all the field data including ground shots, utilities and critical tie-in points. There was one particular area, however, that gave Hudson pause: a 40- acre, concrete cargo area. This “flat” apron is comprised of 107, 20 ft x 20 ft concrete slabs laid in a grid pat-tern. CES was required to locate and pinpoint every concrete joint, or seam, within this vast area, along with any grade change over the cargo space and taxiways. “To acquire that kind of survey over 40 acres would have required us to take 5,000-7,000 shots using our total stations,” says Hudson. “We’d have to set a rod every 20 feet, take a shot, and move to the next point 20 feet away. Although our technology would deliver on the precision, I calculated that it would take eight nights of work to complete it. Hav- ing seen the speed, range and accuracy of the SX10, I thought it might be a better alternative.” He thought right. Arriving on site at 11PM, he and his colleague used the previously established primary control network and set additional “spur” control points as needed. Setting the scanning total station on a chosen control point, Hudson captured the scene, collecting not only the concrete joints and surface elevation variations, but also the tops and bottoms of retaining walls, storm grates and building corners at distances up to Actual scanning image of a portion of the 40-acre concrete cargo area, with dots representing millions of points collected by the SX10.

MARY JO WAGNER is a Freelance Writer, Editor, and Media Consultant based in Vancouver, BC. She can be reached at mj_wagner@shaw.ca.


july 2020


Innovation is the lifeblood of construction and as the industry’s needs have changed so have the means, methods, and materials used to solve challenges. Designers, engineers, and builders search for sustainable solutions to age-old considerations. Yet sometimes there is no substi- tute for tried and true, proven performance. When it comes to perme- able paving systems, there is one proven product that is hard to beat. Used on projects around the country, Grasscrete offers a solid, drivable surface that can be planted with grasses or other vegetation to become completely and naturally concealed. Spanning 1,300 acres, Orange County Great Park is a former Marine Corps Air Station in Irvine, California readapted to be one of the larg- est parks in the world. Meeting California’s landscaping water conser- vation requirements on that size property while creating the necessary vehicular accessibility was no small order. The requirements include establishing a maximum amount of supplemental site irrigation and encouraging 100 percent of groundwater capture and retention onsite. Florasource, Ltd. a California horticultural supply firm supported the buildout with a combination of materials ideally suited for the low- water climate and stormwater retention expectations. “We provided UC Verde Buffalograss and Grasscrete,” shares Flora- source founder, Tom Hawkins. “The grass is a great low-water lawn option that was bred specifically to grow well in drought-prone areas.” Requiring as little as 25 percent of the water of traditional turf grasses, UC Verde Buffalograss peaks at a growth height of just six inches. On the hardscape side, Grasscrete is a sustainable paving solution that was essential in meeting stormwater retention requirements. “Grasscrete is an incredibly durable, permeable paving product that al- lows grasses or other vegetation to be planted within it,” says Hawkins. Manufactured by Sustainable Paving Systems, Grasscrete is a concrete lattice of solid and void that combines the strength and rigidity of a single, structural framework while providing access to soil, water, and sunlight to sustain vegetation. The result is a planted permeable surface that remains drivable when needed. In Irvine, Grasscrete was used to create hard, drivable surfaces for utility access roads, emergency ve- hicle fire lanes, and shoulders for roundabouts in bordering neighborhoods. The key to Grasscrete’s durability is the molded pulp former. This third-generation product allows cast-in-place concrete to be continu- ously reinforced with #4 rebar. Grasscrete's compressive strength is identical to other concrete flatwork, ranging from 45 psi to 6,000 psi depending on the specific mix. An important part of concrete’s strength Here, There, and Anywhere wherever a drivable, vegetated surface is needed, Grasscrete is the answer By Sean O’Keefe

Lafitte Auditorium Grasscrete

is in the thickness of the slab; a minimum of 5.5 inches is recommended for Grasscrete. Like the Orange County Great Park, at the Dr. Martin Luther King Jr. National Memorial in Washington D.C. Grasscrete created a solid, vehicle-accessible walkway as part of a design-build delivery. Build- ers installed paved and plantable access over a 2,000-SF route to the back of an auxiliary building housing the Memorial’s Ranger Station, bookstore, and restrooms. A ramp between the sidewalk and street lets Park Rangers, maintenance vehicles, and deliveries come and go freely while limiting visitor disruptions. At the National Renewable Energy Laboratory (NREL) outside of Denver, Colorado, Grasscrete was incorporated in detention ponds to



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Uniquely, Grasscrete’s patented formers are made of recycled paper pulp. Rather than removing them after the concrete is cured, the 100 percent biodegradable pulp formers slowly begin dissolving after the pour starts. Despite being every bit as durable as a fully poured slab, the Grasscrete system results in 37.5 percent surface and effective void, meaning almost two-thirds of the entire pond surface is open space. This allows the vegetation to truly blanket the concrete surface. In the case of the NREL project, an integral color was added to the mix, making the structure largely disappear altogether. In September 2008, Hurricane Ike destroyed the Town of Jean Lafitte, Louisiana's auditorium while flooding thousands of homes and busi- nesses in Jefferson Parrish. Despite the devastation, the town was de- termined to preserve the auditorium’s landmark location by rebuilding in place. Raising the site out of the floodplain required importing more than nine feet of soil while a pile-supported building was designed for the new 18,000 SF auditorium. Elevating the site so much caused some drainage complications along the parking lot where a steep embank- ment transitions down to a ball field at the original grade. “The slope needed to be stabilized beyond the parking lot because of the steep grade and concerns about erosion,” says Robby Oswald, owner of Bomanite of New Orleans, the contractor hired to resolve the issue. Descending about 7 feet in just 12 feet of distance, rain runoff in Louisiana’s damp climate would likely erode the slope quickly. Once it did, the hill along the heavily trafficked route between Lafitte’s schools and the library would either be an eyesore, dangerous, or both. “Grasscrete was the ideal solution because it allows vegetation to grow within the voids. In this case, it was covered with sod,” continues Os- wald, who along with other Licensees across the country has exclusive rights to this innovative concrete system. “The product is backed by a great company that provides technical support whenever we need it,” says Oswald. “The ability to troubleshoot a project with other Licensed Contractors around the country is always there for us.”

leverage the material’s permeability and durability differently. NREL’s mission is to research and develop clean energy and energy efficiency technologies and related sciences. “As a research laboratory, NREL has been a testing ground for a wide range of pervious concrete systems,” says John Buteyn, Vice President and Technical Manager, at Colorado Hardscapes. “Improving a deten- tion pond on this campus could have long-lasting implications for the way onsite water runoff is managed for generations to come.” Generally integrated into campus settings, detention ponds detain wa- ter onsite to prevent heavy rains from overburdening municipal storm- water systems. Ponds are often planted with wetlands type vegetation to enhance their appearance. As water runs through the pond, a layer of sediment builds up and makes the pond less effective. Once enough sediment accumulates the pond must be scraped; a heavy-equipment process that generally destroys all existing vegetation leaving the need to completely replant the pond afterward. “Grasscrete allows the vegetation to be planted into the concrete so the root systems form below the surface,” continues Buteyn. “When heavy equipment removes the sediment build-up, they can scrape it down to the surface and the plant’s root structures remain intact. This allows it to quickly regenerate without the need for new plantings.”

SEAN O'KEEFE is an architecture and construction writer who crafts stories and content based on 20 years of experience and a keen interest in the people who make projects happen. He can be reached at sean@sokpr.com.


july 2020


Topping off LEED Certification with a Green Roof By Tommy Linstroth

rainwater coming off the building. They can provide an additional layer of insulation, which further reduces heat gain. All of these factors lessen the load on mechanical cooling systems, which lowers energy bills and decreases the wear and tear on HVAC systems. This means less a longer lifespan for what is an expensive capital expenditure. Finally, green roofs can take a space that is typically ignored and turn it into an amenity for building occupants. Well-designed green roofs provide communal meeting spaces and areas to unwind and catch some fresh air during the work day. In addition to providing places of respite for building occupants, green roofs can be functional instead of merely ornamental. Some use cases include space for vegetable gardens or beehives that can actually be used to produce honey onsite. Other Options Green roofs aren’t the only way to reduce the heat island effect produced by buildings. LEED includes a variety of other options including: • Using existing plant material or installing plants that provide shade over paving areas, which can include playgrounds. • Install shade structures that include energy generation systems like solar cells, thermal collectors, or wind turbines. • Install shade structures with specific solar reflectance (SR) values • Building vegetated shade structures.

The crowning achievement of Leadership in Energy and Environmental Design (LEED) certification can be made a little more reachable by incorporating green roof technology into construction projects. Even more importantly, these types of roofs can cut down on cooling costs during the life of the facilities. LEED Credits The green roof requirements are part of a LEED credit meant to en- courage builders to take steps that “minimize effects [of structures] on microclimates and human and wildlife habitats by reducing heat islands,” according to the U.S. Green Building Council (USGBC). There are a number of ways that different types of green roofs contrib- ute to LEED certification. The most common is using a light-colored roof membrane to reflect heat away from the building to keep the inte- rior cooler and reduce its heat-island effect. It’s a matter of basic physics. When exposed to sunlight, dark-colored materials absorb more heat, which increases the amount of cooling needed to keep buildings comfortable. Light-colored roofs, on the other hand, reflect that heat instead of absorbing it, and help keep the interiors buildings cooler. Although a green roof can directly help check off the heat island credit, it can indirectly contribute to meeting other credits as well. If you're trying to manage rainwater onsite, you can contribute to meeting over- all stormwater management credits by installing a vegetated roof. A vegetated roof is exactly what it sounds like: a layer of vegetation, planted over waterproofing material, is installed on top of a building with a flat or only slightly-sloped roof. This can be as simple as basic vegetation planted in a shallow growing medium over a roof or an accessible green space that includes a variety of vegetation, including small trees, that building occupants can enjoy. Finally, many roofing materials have Environmental Product Declara- tions (EPDs) and Health Product Declarations (HPDs), which contrib- ute towards earning the material credits during the

• Using paving materials with specified SR values. • Installation of an open-grid pavement system

• Putting at least 75 percent of parking spaces under cover, using a roofing mate- rial with specific SR values or that is covered with energy generation systems. Keeping Up with Changes Green roofs are a valuable tool for builders seeking LEED certification, but, ultimately, benefit building owners over the long-run in reduced operating expenses and a more comfortable environment. As with any green technology, builders should stay educated on the lasted innova- tions and material options as well as specification changes in LEED or other green rating systems. For example, the USGBC is expected to ratify LEED v4.1, the newest version of the rating system, at some point during 2020. The changes reduce the difficulty of earning some LEED credits without reducing the value of the certification. So, it definitely pays to stay on top of evolving standards.

construction process. Tangible Benefits

In addition to contributing to meeting LEED requirements, green roofs provide tangible benefits to building owners and operators. In addi- tional to reflecting heat, they can be used to help manage and filter

TOMMY LINSTROTH is founder and CEO of Green Badger, a cloud-based solution for equipping project teams of all levels of experience with the tools they need to document LEED as efficiently as possible.



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