ACPA Concrete Pavement Progress - Fall 2022


Concrete Pavement Progress is the official magazine of the American Concrete Pavement Association (ACPA). ACPA is the national trade association for the concrete pavement industry. The primary mission of the ACPA is to lead the promotion of concrete pavement, and align its members, chapter affiliates, and technology partners for effective concrete pavement promotion, advocacy, and technical support on behalf of the concrete pavement industry. Founded in 1963, ACPA is the world’s largest trade association that exclusively represents the interests of those involved with the design, construction, and preservation of concrete pavements. Copyright © 2022 by the American Concrete Pavement Association, Rosemont, Illinois. The contents of this publication may not be reproduced or distributed electronically or mechanically, either in whole or in part, without the express written consent of the American Concrete Pavement Association. AMERICAN CONCRETE PAVEMENT ASSOCIATION 9450 BRYN MAWR AVE., STE. 150, ROSEMONT, IL 60018 phone: 847-966-2272 fax: 847-966-9970 WWW.ACPA.ORG TABLE OF C O N T E N T S ACPA STAFF Laura O’Neill Kaumo President & CEO Andy Gieraltowski Chief Operating Officer Amber Davis Events Coordinator Eric Ferrebee, PE Senior Director of Technical Services Dominic Gatti Communications & Government Affairs Manager Valerie Kliment Assistant Accountant Tim Martin, PE Engineering Services Consultant Anna McMullen Director of Membership & Chapter Relations Gary Mitchell, PE Chief of Engineering & Construction Chrissy Mysko Marketing Manager Larry Scofield, PE Director of Pavement Innovation EDITORIALS Sheryl S. Jackson For ACPA ADVERTISING & DESIGN LLM Publications 503-445-2220 800-647-1511 President Stephen Bloss Sales Representative Grandt Mansfield Design & Layout Jon Cannon 2022 BOARD OF DIRECTORS Ed Griffith, Chairman St Marys Cement Steve Friess, 1st Vice Chair Milestone Contractors, LP Ernie Peterson, 2nd Vice Chair Ash Grove Cement Don Weaver, 3rd Vice Chair Weaver-Bailey Contractors, Inc. David Howard, Immediate Past Chair Koss Construction Dan Rozycki, Treasurer The Transtec Group, Inc. Kevin McMullen, C/S Committee Chair Wisconsin Concrete Pavement Association Steve Ambrose GCC America Patrick Cleary Holcim US Toby Knott Lehigh Hanson, Inc. Bob Leonard GOMACO Corp. James Mack CEMEX Don Metcalf Webber, LLC Jason Reaves, C/S Committee Vice Chair South Dakota Chapter, ACPA Nathan Reede Reede Construction, Inc. John Roberts, Ex Officio IGGA Dave Sciullo Golden Triangle Construction Co., Inc. Rick Sniegowski K-Five Construction Ed Wessel Hi-Way Paving THE OFFICIAL PUBLICATION OF THE AMERICAN CONCRETE PAVEMENT ASSOCIATION / ACPA.ORG PAVEMENT PROGRESS FALL // 2022 FEATURED ARTICLES COVER FEATURE 08 Project Profile: I-70 Indianapolis Silver Linings from COVID Shutdown: Total Interstate Closure Accelerates Construction, Brings Increased Scope of Work 10 Emerging Technologies Innovation for the Future of the Concrete Pavement Industry 15 Measuring Pavement Sustainability: The Importance of Use Phase Impacts IN EVERY ISSUE 04 CEO’s Message Younger Generations Show Commitment to Sustainability and Resiliency By Laura O’Neill Kaumo 19 Legal Matters The Other Differing Site Condition By Thomas R. Olson & Rielly J. Lund 22 ACPA News 22 ACPA Launches Product Innovation Showcase 22 Stay Up-to-date with ACPA 24 Advertiser Index 08 10 15

CONCRETE PAVEMENT PROGRESS 4 WWW.ACPA.ORG THE 2022 MIDTERM ELECTIONS IN THE UNITED STATES ARE LARGELY BEHIND US AND THE RESULTS SURPRISED MANY. While recounts and runoffs may continue beyond November, the exit polling is showing that Generation Z voted with much higher turnout than anticipated—proving that when issues younger voters care about are on the ballot, they vote. In a recent article, Time magazine noted, “Gen Z power is only growing, and it will permanently change the dynamics of our elections. They comprise 10% of eligible voters already, a share that will increase with each passing day as more age into the electorate.” So, what does Gen Z care about? It may in part be the economy stupid, as James Carville famously said, but it’s not at the expense of social issues including climate change and equity. For transportation investment, as Generation Z ages and begins to ascend into positions that shape our world, it is likely that sustainability, resiliency, and equity continue to be part of guiding investment because it’s part of the lexicon of younger generations. In short, consumers and voters will continue to demand it. One may then think that concrete as a vital building material since ancient times is yesterday’s news when considering the future of surface transportation construction. This assumption is fundamentally wrong. Concrete paving strongly aligns with the objectives of battling climate change when the entire life of the pavement is considered. The challenge presented to global and local communities is how to build more durable structures using concrete, while minimizing the carbon emissions generated during manufacturing of cement. But as the Portland Cement Association’s (PCA) Roadmap to Carbon Neutrality points out, calling for more concrete pavement projects creates a safe, reliable, cost-effective, sustainable, and resilient infrastructure network that achieves a goal for net-zero CO2 emissions by 2050. Its about looking at the complete picture. Younger Generations Show Commitment to Sustainability and Resiliency Holistically, any discussion of sustainability and climate change should also include the relevance of concrete’s resilience. Sustainability and resilience work in tandem, with resilience forming the foundation for all three pillars of sustainability—economic, environmental, and societal demands. While sustainability deals with known events that can be quantified, resilience is the ability to anticipate and adapt to changing conditions and recover rapidly after a disruptive event. Unlike sustainability, resiliency deals with unknown events that have high negative impacts like loss due to flood, earthquake, etc. In a changing climate where extreme weather events are greater in frequency and intensity than in the past, resiliency is an important consideration. When properly maintained, concrete pavements can last decades and are often highly capable of withstanding natural disasters—what’s more sustainable than that? Concrete paving is wellpositioned to address the societal goals of the future as it is estimated that every $1 invested in more resilient infrastructure results in $4 of long-term benefit over the infrastructure’s expected life. As such, decision-makers and specifiers will be called on to design pavements that are sustainable and will not fail in the face of disastrous events. With all things considered, concrete, an ancient building material, is the material of the future. Laura O’Neill Kaumo President & CEO American Concrete Pavement Association Laura O’Neill Kaumo President & CEO American Concrete Pavement Association




CONCRETE PAVEMENT PROGRESS 8 WWW.ACPA.ORG Project Profile: I-70 Indianapolis Silver Linings from COVID Shutdown: Total Interstate Closure Accelerates Construction, Brings Increased Scope of Work By Sheryl S. Jackson Closing one or more lanes on any road is disruptive to travelers and businesses, but when a road’s traffic volume typically exceeds 170,000 vehicles each day, closures of any length of time are only made when necessary for repair and maintenance. However, COVID and the associated changes in business openings, remote workforces, and cancellation or delay of major events, including the Indianapolis 500, provided an opening that the Indianapolis Department of Transportation (INDOT) and contractors could not have predicted. The 40 percent decrease in traffic allowed INDOT to shut down a 6-mile section of I-70 for a repair project in Indianapolis. The highway was shut down completely from I-465 to the I-65/I-70 North split, and traffic was rerouted to alternate roads on April 13, 2020. The section re-opened prior to Memorial Day. “We proposed the closure and acceleration of the project start date in a meeting with INDOT because the construction industry was allowed to continue working,” explains Terry Burris, Concrete Division General Superintendent for Milestone Contractors LP. Each direction of traffic was closed in 30-day increments, allowing construction to proceed more quickly and safely. The full closure also allowed a closer inspection of the pavement, and the project grew from 17,163 square yards of full-depth PCCP patching and 111,761 square feet of partial-depth joint repair as bid, to more than 30,600 square yards of fulldepth PCCP patching and 180,400 square feet of partial-depth joint repair. The scope increased by 78 percent for full depth and 61 percent for partial depth repairs. “Closing the highway to traffic on the segment inside I-465 reduced two or three months’ worth of

WWW.ACPA.ORG 9 FALL // 2022 work in each direction to 30 days of work, which benefited drivers,” says Jason Mathias, P.E., PMP, of Burgess & Niple. In addition to the mainline paving, exit ramps in the closed section were also repaired at the same time. “Cost savings related to the full closure totaled $4.8 million before the additional scope of work was added to the project. Construction traffic control outside I-465 followed the initial plan with phases divided into segments between interchanges.” Meeting the Challenges Even with a full closure on part of the project, there were some challenges. “The biggest hurdle was getting trucks in and out of the construction zone,” Burris says. “To help get materials to and from the site, Indiana State Police helped by implementing rolling roadblocks to open the road to trucks.” The other challenge was ramping up to meet the supply and staffing demand created by the enhanced scope of work and a relatively short timeframe for the full closure of the segment inside I-465. “All our personnel came together, and we ramped up the number of crews to work on the project,” says Burris. “We had internal personnel who were scheduled for other projects that had not yet started, so we moved them to our project.” Even with additional personnel, the real reason Milestone completed the project on time was the teamwork among all crews. “We had so many facets of construction going at one time—digging, joint repair, full-depth repair—that crews would move back and forth to help each other,” Burris says. “This approach continues within the company and on all of our projects, and it is good for the company, our clients, and our employees. Employees like learning new skills, and I always tell them that becoming versatile is good for their career, and they enjoy their success of being challenged and learning.” Working together as a team included an innovative invention by Milestone’s equipment department. Combining a rubber-tired excavator with a Minnich drill sped up the drilling operation. “It was important on this project, but we have used it every day on other projects since then,” says Burris. Because Milestone had to complete 1 to 2 miles of joint repair per shift, good control of the mix was essential. A very consistent mix capable of producing reliable high-strength break results was also needed, and volumetric concrete mixers provided the solution to both requirements. “The convergence of a pandemic-related decrease in traffic volume that enabled the complete closure of a section of highway, the availability of personnel within Milestone, and the teamwork exhibited by Milestone employees and INDOT Representatives and Engineers made it possible to meet deadlines despite an expanded scope of work,” says Burris. “We had a window of opportunity to make this work, and the stars lined up for us!” INDIANAPOLIS, IN Benefits of Concrete Pavement for I-70 • The long life of concrete pavement means there will be minimal major traffic disruptions to the highway over the coming decades • The rigid pavement will reduce fuel consumption for vehicles traveling this stretch of I-70, saving money and carbon emissions • The durability of concrete pavement will help avoid perpetual maintenance, saving the state and taxpayers money

CONCRETE PAVEMENT PROGRESS 10 WWW.ACPA.ORG Emerging Technologies Innovation for the Future of the Concrete Pavement Industry By Sheryl S. Jackson Steve Jobs famously said, “Innovation distinguishes between a leader and a follower.” When examining concrete pavement through this lens, one can see how the industry is leading through innovations. In this final segment of a two-part series on innovations in the concrete pavement industry, ACPA examines how innovative concrete pavement engineers and researchers are creating solutions today that will become the basis for building resilient, sustainable, cost-effective, and long-lasting pavements in the future. Editor’s Note: To see part one, refer to Concrete Pavement Progress, Quarter 2, 2022: Innovative Approaches Address Today’s Challenges, p. 10. Self-Healing Concrete Pavement: Extending Pavement Life Concrete pavements are already well-known for their resilience and long lifespan. However, an emerging technology promises to improve upon these characteristics even more. The key? An enzyme that promotes the growth of calcium carbonate crystals to fill cracks as they develop. Although still in the research phase and a few years from testing in the field, lab results have demonstrated self-healing samples with millimeter-scale flaws heal within 24 hours. This is significantly faster than other methods, such as the use of bacteria, which requires a minimum of 28 days for strength recovery of microscale cracks.1 “The Carbonic Anhydrase (CA) enzyme can be added to the concrete mix to create a selfhealing material to apply to cracked concrete or mixed into fresh concrete to create a pavement that can heal itself over time,” says Jessica A. Rosewitz, P.E., Ph.D., Assistant Teaching Professor of Civil, Environmental and Architectural Engineering at Worcester Polytechnic Institute and co-author of the research article describing the process. “The CA enzyme uses CO2 and a calcium source to create calcium carbonate, our healing material. When a crack forms in enzymatic concrete, exposing the enzyme to CO2 in the air triggers the growth of a new matrix that fills the crack.” The process is also environmentally sound. “The enzyme absorbs CO2 to heal the pavement, which reduces greenhouse gases,” Rosewitz adds. Healing small cracks as they develop prevents them from growing into larger cracks or faults that affect the pavement’s strength, water tightness, and durability, which reduces maintenance requirements and extends the concrete pavement’s already long lifespan. Internal Curing: Minimizing Cracking In 2010, the early use of internal curing for concrete began on bridge decks in Indiana and New York. Unlike conventional curing, which supplies water from the concrete’s surface, internal curing provides curing water from the aggregates within the concrete. While external water can only penetrate to a limited depth, using expanded lightweight aggregate for internal curing disperses water throughout the depth of the concrete. “Internal curing has proven to reduce shrinkage cracks and fluid transport and increase hydration,” said Jason Weiss, Ph.D., Professor of Civil and Construction Engineering at Oregon State University. “In Indiana, the use of internal curing and high-performance mixture has tripled the life of the bridge.” Following Indiana and New York, states including Ohio, Iowa, Utah, and many others

WWW.ACPA.ORG 11 FALL // 2022 continues on page 12 » began adopting internal curing methods for bridge decks. Pavements have been constructed in Texas and by the Illinois Tollway, said Dr. Weiss. “There are now numerous states allowing internal curing of concrete pavement, and more state Departments of Transportation are open to the technology. “Porous, lightweight aggregate is plentiful in most regions of the country, so supply is not a challenge,” says Weiss. “The greatest challenge is controlling the moisture of the aggregate. While the Illinois Tollway was a mainline pavement, some of the most common uses for internal curing include patching, bridge decks, and continuously reinforced concrete pavement (CRCP).” According to a Federal Highway Administration Tech Brief, “The water that is absorbed in the lightweight aggregate does not contribute to the classic definition of the water-to-cement ratio. The water-to-cement ratio is a descriptor of the structure of the matrix and pores that develop in the fluid concrete system. Once the concrete sets, the structure and pore network have been established, and water can only aid in hydration. The water in the lightweight aggregate will desorb (leave) the pores of the lightweight aggregate as the negative pressure in the pore fluid develops with setting and increases thereafter.”2 “Studies by Rao and Darter also suggested several benefits of using internal curing in pavements,” said Weiss. One of the benefits includes a reduction in curl in CRCP.3 Field tests of internal curing on two test sections containing lightweight fine aggregate (LWFA) performed by the National Concrete Pavement Technology Center4 found: • Internal curing improved the degree of hydration over time. • The inclusion of LWFA did not affect maturity. • The internal curing reduced temperature and moisture differentials in the system. • Hence, warping and curling were reduced significantly. This is a benefit, as ride is improved, and the risk of corner breaks is reduced. Based on this observation, it is likely that slab sizes can be extended for thinner sections, thus keeping saw-cuts out of the wheel path. • The permeability of the mixture containing LWFA was found to be improved— potentially increasing the pavement’s longevity. • Structural design modeling did not reflect any changes for traffic loadings on these pavements. • A life-cycle cost analysis indicated a longterm financial benefit to the technique based on reduced frequency of rehabilitation work and extended predicted life. • Reports from construction sites indicated that storing and preconditioning the LWFA would be a challenge in larger applications; otherwise, no significant changes were observed. Battery Powered Equipment: Green Alternative on Horizon The automotive industry’s push to increase the number of electrified vehicles in their portfolios raises the question: What pavement construction equipment can be electrified? The question was answered with GOMACO’s introduction of the first battery-powered curb machine. “We started with the curb and gutter slipform paver due to the size and power rating,” says Kevin Klein, Vice President of Engineering/ Research and Development. “Initially, our main objective for a smaller machine was achieving a full day of paving with a single charge in the most cost-effective way possible. Now that battery technology is increasing, we’re looking at the possibility of electrifying the rest of the GOMACO lineup.” At this time, the battery-powered curb and gutter slipform paver is still being used for research and testing but have been used on several job sites as part of the testing phase. One of those job sites was a 15,000-linear foot job which included a The automotive industry’s push to increase the number of electrified vehicles in their portfolios raises the question: What pavement construction equipment can be electrified? The question was answered with GOMACO’s introduction of the first battery-powered curb machine.

CONCRETE PAVEMENT PROGRESS 12 WWW.ACPA.ORG » continued from page 11 curb profile for a large parking lot and distribution center. To date, performance has been as expected based on our engineering study done before implementation. Benefits of battery-powered equipment on a job site include reduced noise and emissions. “This technology benefits the industry by helping secure jobs where emissions could be a problem, for example, tunnels, inside buildings, and parking garages,” says Klein. “There is also potential for tax breaks for going green.” Challenges, at least for early adopters when electric pavers are available, can include higher up-front costs and availability of charging arrangements. “The major challenge is charging,” Klein explains. “It’s not as simple as just filling up with fuel the next morning. The machine can handle a full day of paving but needs to be charged in one of two ways, either a seven-hour ‘overnight’ charge or a two-hour quick charge.”

WWW.ACPA.ORG 13 FALL // 2022 Either one of those can be accomplished by taking the machine to the shop overnight or by possibly having power at the job site. When either of those are not available, a generator is needed to recharge the machine. “The next steps of development are to keep developing machines with the latest in new technologies and also research alternative ways to get efficient power, whether that’s hydrogen-powered, diesel hybrid, or fully electric,” says Klein. “We’ll be exploring voltages and efficiencies for our larger machines. The timeline is difficult to predict at this point because of component shortages and other challenges currently at work in the marketplace.” Inductive Charging in Pavement: Meeting Needs of EVs As more electric vehicles are used by the general public and truck-based transportation companies, conversations about the infrastructure to provide convenient, accessible charging stations become more critical. An alternate to constructing dedicated charging stations for EVs is to turn the pavement into one long, seamless charging “station” that enables a driver to recharge while on the road. Eliminating the need to stop and plug in throughout the day increases the feasibility of EVs for commercial applications such as logistics, transit, and transportation. Inductive charging in the pavement also addresses the challenge of providing charging areas at multi-family sites such as apartment or condo buildings and office or retail spaces. Embedding the charging coils in the concrete pavement also works with parking lots and onstreet parking, says Tim Sylvester, founder and CEO of Integrated Roadways. When the concrete pavement charges the vehicle, there’s no need to plan dedicated spaces for EVs. “An application that is flexible and works as a dynamic as well as a static charger, future-proofs the pavement,” Sylvester explains. Precast concrete panels with technology built into each panel, or Smart Pavement, enable wireless charging along with other functions. “In most in-motion applications, only one in five to one in eight Smart Pavement slabs needs to have charging coils inside to keep your vehicle charging,” says Sylvester. His company’s product also embeds other digital technology and fiber optic connectivity for traffic data collection through in-road sensors. The pavement is modular and designed to be easily upgradeable. It enables Wi-Fi access, 5G, wireless EV charging, edge data, and cloud services and more through a connected network of systems, sensors, and antennas. Adding the technology in the factory results in faster construction of the pavement and greater quality. The contractor sets up the base and subgrade of the road as it has always been done, then lifts the panels into place. “We took pains to make the construction process simple,” Sylvester says. “After placing and leveling the panel, dowels are extended into the adjacent pavement.” As more electric vehicles are used by the general public and truck-based transportation companies, conversations about the infrastructure to provide convenient, accessible charging stations become more critical. An alternate to constructing dedicated charging stations for EVs is to turn the pavement into one long, seamless charging “station” that enables a driver to recharge while on the road. Other benefits include the need for smaller crews to construct the roadway and a simpler repair if a panel needs to be replaced—just remove one panel and replace it with another, he adds. Demonstration projects in Colorado, Kansas, and Missouri have proven the construction and technology work, said Sylvester. “We are moving toward the next step of a larger installation that can showcase all of the benefits.” References 1. Rosewitz, J, Wang S, Scarlata S, Rahbar N. An enzymatic self-healing cementitious material. Applied Materials Today. 2021. 23. 101035. 10.1016/j. apmt.2021.101035. 2. Weiss J. Internal Curing for Concrete Pavements. Tech Brief. Federal Highway Administration. July 2016. 3. Rao C, Darter M. Evaluation of Internally Cured Concrete for Paving Applications. Applied Research Associates, Champaign, IL. 2013. 4. Daghighi A, Taylor P, Ceylan H, Zhang Y. Impacts of Internally Cured Concrete Paving on Contraction Joint Spacing, Phase II: Field Implementation of Internally Cured Concrete for Iowa Pavement Systems. National Concrete Pavement Technology Center, Iowa State University. April 2021.


WWW.ACPA.ORG 15 FALL // 2022 continues on page 16 » Measuring Pavement Sustainability: The Importance of Use Phase Impacts By Sheryl S. Jackson As the focus on sustainability at federal and state levels continues, the concrete pavement industry is poised to continue sharing the sustainable benefits of concrete pavements over alternative solutions. The entire cement-concrete industry has committed to carbon neutrality by 2050, as detailed in Portland Cement Association's Roadmap to Carbon Neutrality, and has already made great strides in reducing CO2 emissions in the creation of concrete and the construction of pavements. As the industry works toward this goal, it remains increasingly important to consider CO2 emissions throughout the pavement’s life—not just during the initial construction. The Federal Highway Administration (FHWA) and state Departments of Transportation have been considering sustainability in pavements over the past ten years, but the challenge has been how to determine what data is needed and how to gather and measure it, says Jim Mack, P.E., Director of Market Development at CEMEX. “We are getting closer to developing tools we need, but most life-cycle assessments (LCAs) of environmental impacts miss the use phase of the pavement,” Mack says. “We can more easily quantify embodied emissions—those emissions associated with materials, initial construction, maintenance, and rehabilitation—rather than emissions that are increased, or decreased, during use of the pavement over its life.” “Including use phase in any life cycle assessment is critical because the concrete pavements are assets that will last 30, 50 or more years,” says Eric Ferrebee, P.E., Senior Director of Technical Services at the American Concrete Pavement Association. “We know the importance of measuring greenhouse gas emissions in the manufacture of cement and can quantify that amount, but agencies are just starting to become interested in capturing data on what happens over the pavement’s lifetime.” Two important use phase factors identified by researchers at the Concrete Sustainability Hub at Even after a concrete pavement’s service life, it provides an environmental benefit by sequestering and storing carbon dioxide.

CONCRETE PAVEMENT PROGRESS 16 WWW.ACPA.ORG » continued from page 15 the Massachusetts Institute of Technology (MIT CSHub) are pavement-vehicle interaction (PVI) and albedo. PVI describes the excess fuel emissions/energy from vehicles due to excess rolling resistance between the pavement and the vehicle. Albedo is the fraction of solar energy reflected by the Earth's surface; lighter-color, higher-albedo surfaces reflect more energy than lower-albedo, darker surfaces.1 The less bumpy a road is, the less energy is needed for a vehicle to travel the pavement, which means less fuel needed, and fewer emissions explained Ferrebee. Concrete is an inherently stiff pavement which reduces deflection-related PVI. “There are three pavement vehicle interactions that impact excess fuel usage,” Mack says. “Researchers at MIT CSHub have now quantified that data and demonstrated how emissions are affected by these factors.” The three factors include: 1. Smoothness/Roughness (IRI): The excess energy needed to overcome the frictional forces in the vehicle suspension due to the bouncing of the car.2 2. Structural/Deflection: The excess energy required to traverse or drive uphill due to the deflection or bending of pavement from the weight of the vehicle.3 3. Surface Texture: The excess energy required to overcome the abrasiveness or macro texture at the tire-pavement contact area—a factor that is critical for safety. The measurement of PVI is always important no matter what type of traffic is common on the road, says Mack. “PVI from roughness is the one everyone pays attention to now because it affects cars and trucks. It evolves over time and is a function of how well we maintain our pavement smoothness,” he says. “PVI deflection is a measurement that depends on pavement type/ design. Because concrete is naturally stiffer, it has lower PVI deflection, and this is what matters—especially on corridors with medium to high truck volume.” “Another important factor is the albedo effect— the reflection of sunlight back into the atmosphere,” says Mack. “Dark pavements absorb the heat, then release it later as the atmosphere cools at night, creating ‘heat islands.’ Lighter pavements, such as concrete, reflect light and heat, so it dissipates throughout the day.” “Concrete’s albedo is closer to the overall average of Earth’s albedo,” Mack explains. “Earth’s average is about 0.33, and concrete is 0.2 to 0.35, depending on the age and mix components. Asphalt pavements’ albedo starts out low, around .1, because they are black and lighten over time.” After 10 to 15 years, asphalt pavements are rehabbed, which makes them black again. Concrete starts out at a much higher albedo, and over time, it darkens, but it never darkens to the point that it is darker than asphalt—it is always lighter. When concrete is rehabbed with diamond grinding, it returns to its original, higher albedo. “Studies have shown in some cities, such as Phoenix, temperatures could be reduced by a few degrees when using a lighter pavement material such as concrete,” says Ferrebee. Understanding the effect of pavement that absorbs and holds heat is important to understanding how urban heat islands create greater greenhouse gas emissions. At this time, no state agencies are making decisions based on greenhouse gas emissions, but Credit Jacquelyn Wong, Caltrans “The concrete pavement industry has been talking about use-phase impacts for more than a decade, but it’s important to get our message out that including use-phase emissions is valuable data that provides a better view of environmental impact over the pavement’s life.” Eric Ferrebee, P.E., Senior Director of Technical Services, American Concrete Pavement Association

WWW.ACPA.ORG 17 FALL // 2022 some states are evaluating upfront construction impacts to gather data for the creation of baseline measurements. “The concrete pavement industry has been talking about use phase impacts for more than a decade, but it’s important to get our message out that including use phase emissions is valuable data that provides a better view of environmental impact over the pavement’s life,” Ferrebee says. Mack agrees: “Measuring the use phase impacts as part of the overall analysis will allow departments of transportation to make the right decisions because they have the right information,” he says. “This doesn’t mean that concrete is always the right choice for a project. It depends on the type and volume of traffic, geographic location and climate, among other factors. We want decisions to be made fairly, with complete information, so the right application is chosen for the right reasons.” Using performance-engineered mixes, optimizing the design to avoid overbuilding, reducing clinker and increasing the use of portland limestone cement and supplementary cementitious materials all contribute to the reduction of greenhouse gases, but the conversation around reducing concrete pavement’s life-cycle impact on the environment should continue. “This requires an ongoing conversation about accurately measuring emissions throughout the life of a pavement, not just in the manufacture of materials or initial construction,” Ferebee says. References 1. Akbarian M, Ulm FJ, Xu X, Kirchain R, Gregory J, et al. 2019. “Overview of Pavement Life Cycle Assessment Use Phase Research at the MIT Concrete Sustainability Hub.” Airfield and Highway Pavements 2019: Innovation and Sustainability in Highway and Airfield Pavement Technology— Selected Papers from the International Airfield and Highway Pavements Conference 2019. 2. Zaabar I, Chatti K. 2010. Calibration of HDM-4 Models for Estimating the Effect of Pavement Roughness on Fuel Consumption for U.S. Conditions. Transportation Research Record: Journal of the Transportation Research Board, No. 2155. Pages 105–116. 3. Akbarian M, Moeini SS, Ulm F-J, Nazzal M. 2012. Mechanistic Approach to PavementVehicle Interaction and Its Impact on Life-Cycle Assessment. Transportation Research Record: Journal of the Transportation Research Board, No. 2306. Pages 171–179.


WWW.ACPA.ORG 19 FALL // 2022 continues on page 20 » NEARLY EVERY PUBLIC CONSTRUCTION PROJECT has a differing site condition clause. The purpose is two-fold: to allow contractors the confidence to submit accurate bids and allow government owners to benefit from not having large contingencies unnecessarily inflating costs. This principle has been expressed around the country in various ways, but we think it is nicely summed up in PT & L Const. v. Dept. of Transportation: The purpose of the changed conditions clause is thus to take at least some of the gamble on subsurface conditions out of bidding. Bidders need not weigh the cost and ease of making their own borings against the risk of encountering an adverse subsurface, and they need not consider how large a contingency should be added to the bid to cover the risk. The Government benefits from more accurate bidding, without inflation for risks which may not eventuate. 108 N.J. 539, 531 A.2d 1330 (1987), quoting Foster Constr. C.A. & Williams Bros. Co. v. U.S., 193 Ct. Cl. 587, 435 F.2d 873, 887 (1970). Nearly all contractors approach the DSC by looking to the borings or other geotechnical data included with the bid documents. For example, the borings may indicate some gravel and maybe cobbles, but when the contractor begins excavation work in an area they discover a boulder field. This is known as a “Type I” DSC, or a condition that is differing materially from the conditions “indicated” in the project documents (including the geotechnical information, plans, specs., etc.). But what happens when the borings don’t necessarily contradict the materials encountered, or there are not any borings to begin with? This is where the “other DSC” comes into play. A “Type II” DSC is an “unknown physical condition of an unusual nature, differing materially from those ordinarily encountered and generally recognized as inherent in the work provided for in the contract.” 48 CFR 52.236-2. Unfortunately, many contractors either forget or do not understand that they have rights beyond the “typical” Type I DSC claim. Furthermore, The Other Differing Site Condition By Thomas R. Olson & Rielly J. Lund when contractors do submit a Type II DSC claim, they are often denied by the project engineer because “the contract documents do not contradict the on-site materials.” Or, as nearly every DSC denial states, the engineer believes “the contractor should have anticipated” the material despite zero actual evidence in the contract. (A personal favorite was an engineer pointing to the IDOT Standard Specifications, which contained a standard rock excavation clause for why the contractor should have anticipated potential rock excavation.) Fortunately, contractors do not need to plan for the worst in order to “reasonably anticipate” what the conditions will be on-site. One area where we have been successful with this in the past, is when the soil classifications are the same as indicated in the contract documents, but they react in an unanticipated manner. For example, let’s say on a road you need to excavate a portion beyond the existing roadbed, for whatever reason. There are soil borings provided, that indicate clays and gravel, and also the “N” values, plasticity, water content, etc. Now you get out there and find that the excavation is much more difficult than anticipated. In fact, the soils are so hard that it is taking nearly twice as long to excavate before you are able to move the project along. This is a prime example of when a Type II DSC could be applicable. It has long been held that a Type II DSC exists when an anticipated soil reacts in an unanticipated manner. “[T]he proof in this case is that the material encountered did not react as anticipated.” Appeal of T & B Builders, Inc., ENG BCA No. 3664, 77-2 BCA ¶ 12663 at 6 (emphasis added). See also Appeal of Ballenger Corp., DOTCAB No. 7432, 84-1 BCA ¶ 16973 at 44 (“reaction of the soil to the excessively moist environment was both unusual, unknown and materially different from what either party expected”). One case that goes into substantial detail regarding this is Servidone Const. Corp. v. U.S., 19 Cl. Ct. 346 (Ct. Cl. 1990): There are certainly no affirmative indicators that the soil would not be tough, and the court declines to hold that the absence of an indication of toughness is an implied assurance that the soil was not tough. Servidone is essentially asking the court to compare the actual conditions to what they argue were the normal or average conditions typically encountered in similar projects. Such a comparison, however, is more appropriately advanced in a Type II, rather than a Type I analysis. [360] ■ ■ ■ Servidone alleges that the fill materials at the Joe Pool Lake site were of a highly unusual character; that they were extremely tough in a way that Servidone could not have anticipated; and that this toughness added dramatically to the cost of completion. It also asserts that part of the cause of the toughness of the soils is that they contain poorly crystallized or non-crystalline montmorillonite and calcium carbonate, which, when wet, form a highly unusual inorganic jelly-like substance. [360] Numerous Board1 decisions also support the above proposition. See, e.g., Appeal of MC Co., ASBCA No. 21403, 78-2 BCA ¶ 13,313 (June 21, 1978) (Water could have been anticipated in the project and contract documents, but not to the extent that it came in and caused such issues: sloppy, soupy, could not place pipe or machinery on without sinking, had to change means and method); In Re Appeal of Fed. Ins. Co.¸IBCA No. 3236, 96-2 BCA (CCH) ¶ 28415 (July 2, 1996) (Although conditions may have been anticipated to a degree, this will not preclude recovery when actual conditions were in a higher proportion than anticipated. A reasonable contractor is not held to knowledge that a geologist may have, and uncharacteristic hardness warranted a Type II DSC); Appeal of Paccon, Inc., ASBCA No. 7643, 1962 BCA (CCH) ¶ 3546 (Oct. 17, 1962) (Although the type of material—Shimajuri clay—was known to be in the area, the condition and reaction of this particular clay was not); Appeal of Warren Painting Co., Inc., ASBCA No. 18456, 74-2BCA (CCH) ¶ 10834 (Sept. 13, 1974) (Although contractor was experienced in L E G A L M A T T E R S

CONCRETE PAVEMENT PROGRESS 20 WWW.ACPA.ORG LEGAL MATTERS Contact us today! Grandt Mansfield 503-445-2226 | area and knew of propensity for water, the way water reacted in this case—spurting, bubbling, and creating more runoff—could not have been anticipated). So, next time you encounter something that costs you more time and money on a project, don’t give up just because there either isn’t any indication in the contract documents, or the material is indicated but reacted differently. You need to ask yourself whether the material you encountered and the way in which the material behaves should have reasonably been anticipated, not whether it possibly could have been. If you do not believe it would have been reasonable, you have a good faith basis to seek your increased costs, despite the inevitable pushback you will likely receive from the engineer. In your discussions, simply ask the engineer to provide you with any information they believe should have indicated the condition on this particular project, and not just in general (like the engineer in Iowa who believed the standard specifications meant the contractor should have anticipated rock excavation). If they cannot point to something specific, why should the contractor have inflated its bid unnecessarily? It is often helpful in these situations to point out the underlying purpose behind the DSC clause to help the engineer and the owner understand why they should be reasonable in the acceptance or denial of a DSC claim. References 1. Board Decisions are often excellent places to look for well-reasoned precedent on Federal Projects, due to the specialized nature of the cases the administrative judges assigned to the boards often have a much better understanding of the technical aspect of the construction process. And, although not binding, when the particular issue has not been addressed in your jurisdiction, the reasoning of the Board Decision can be used for guidance. Thomas Olson is the founding partner of Olson Construction Law. Tom’s commitment is to provide guidance on how to resolve issues on the jobsite, not in the courtroom. Tom has worked on highway heavy projects throughout much of the United States for more than thirty years. A prolific speaker and writer as well as attorney, his expertise is in concrete and asphalt paving, utility, earthwork and bridge construction, schedule analysis, material testing, and the technical and legal obligations of both engineers and contractors. Rielly Lund is a committed advocate for contractors, with the ability to quickly and accurately analyze a client’s issue within the parameters of each specific contract. Rielly works with contractors through all stages of construction, from bidding to acceptance, with the goal of minimizing risk and maximizing profits for contractors. With this in mind, Rielly enjoys discussing various contractual requirements with contractors before issues arise, so they are best able to meet any challenges head on. ABOUT THE AUTHORS » continued from page 19

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CONCRETE PAVEMENT PROGRESS 22 WWW.ACPA.ORG PRODUCT NEWS ACPA Launches Product Innovation Showcase: Feature Your Innovative Projects Here STARTING IN THE WINTER 2023 ISSUE OF CONCRETE PAVEMENT PROGRESS, ACPA will begin featuring a “Product News” section to highlight innovative products and research from around the concrete pavement industry. If you have a product or technology that you would like to share, please scan the QR code on the right or email ACPA’s Director of Member and Chapter Relations, Anna McMullen, at Stay up-to-date with ACPA Keep abreast of industry news, ACPA happenings and professional development opportunities by following us on LinkedIn, Twitter and Facebook. @paveconcrete @paveconcrete63 American Concrete Pavement Association ACPA NEWS

ACPA NEWS CONCRETE PAVEMENT PROGRESS 24 WWW.ACPA.ORG Advertise in Concrete Pavement Progress! Published quarterly, Concrete Pavement Progress disseminates industry news, best practices, and networking events nationally to all members of the American Concrete Pavement Association (ACPA). The ACPA is the world’s largest trade association that exclusively represents the interests of those involved with the design, construction, and preservation of concrete pavements. ADVERTISING RATES STARTING AT $280! • Discounted ACPA Member Rate • Advertiser Index American Engineering Testing 18 APR Consultants, Inc. 17 Ash Grove Cement Co. 7 Cesare, Inc. 7 Continental Cement 14 Crafco, Inc. Inside Back Cover E2 Systems, LLC 21 Erie Strayer Company 1 Flores Automation 21 GOMACO Corporation Back Cover Guntert & Zimmerman 23 Lehigh Hanson, Inc. 6 Minnich Manufacturing 5 Olson Construction Law 20 Power Curbers Inside Front Cover Pugmill Systems, Inc. 22 Road and Runway, LLC 18 Shumaker Industries 14 The Bay Family of Companies 18 Wirtgen America, Inc. 2

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