Introducing the Reduced Carbon Concrete Consortium SUMMER / 2024
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 THE OFFICIAL PUBLICATION OF THE AMERICAN CONCRETE PAVEMENT ASSOCIATION / ACPA.ORG PAVEMENT PROGRESS SPRING // 2024 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 Valerie Kliment Assistant Accountant Tim Martin, PE Engineering Services Consultant Kelsey Carriere Director of Membership & Chapter Relations Gary Mitchell, PE Chief of Engineering & Construction Larry Scofield, PE Director of Pavement Innovation Emily Emanuelsen Publications Coordinator, AOE Kristin Dispenza Contributing Writer, AOE ADVERTISING & DESIGN Big Red M www.bigredm.com Sales Representative Ronnie Jacko Ronnie@bigredm.com Design & Layout Shelby Bigelow 2024 BOARD OF DIRECTORS Ernie Peterson, Chairman Ash Grove Cement Company Don Weaver, 1st Vice Chair Weaver-Bailey Contractors, Inc. Patrick Cleary, 2nd Vice Chair Holcim U.S. Ed Wessel, 3rd Vice Chair Hi-Way Paving Dan Rozycki, Treasurer The Transtec Group Steve Friess, Immediate Past Chair Milestone Construction LP Bryan Beck GOMACO Joey Biasatti Continental Cement Joe Finnegan GCC America Joel Galassini CEMEX Tim Gerhardt Koss Construction Co. Ruben Guerrero Salt River Materials Toby Knott Heidelberg Materials John Leckie Indiana Chapter, ACPA Greg Mulder Iowa Concrete Paving Association Tim Nash Wirtgen American, Inc. Greg Pelkey Shafer Contracting Co. Nathan Reede Reede Construction, Inc. John Roberts Intl. Grooving & Grinding Assn. Dave Sciullo Golden Triangle Construction Jake Steinberg American Highway Joe Weishaar William Charles Construction 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 © 2024 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. FEATURED ARTICLES COVER FEATURE 08 Introducing the Reduced-Carbon Concrete Consortium (RC3) Reducing carbon in the construction process. 10 Roundabouts: A Construction Curve Ball 12 Diamond Grinding Offers Solutions to Many Pavement Challenges 17 100-Year-Old Highway Shows a Legacy of Durability and Smart Investment IN EVERY ISSUE 04 CEO’s Message Editorial Summer 2024 19 ACPA News Stay Up-to-date with ACPA 20 Advertiser Index 12 08
CONCRETE PAVEMENT PROGRESS 4 WWW.ACPA.ORG How America funds infrastructure must change. Our current process is a can we have kicked down the road for quite some time. Simply, the once reliable “gas tax” continues to become woefully inadequate as an overall funding source. Further, our world is rapidly changing—the demands and lifestyles of users are dramatically different than what they were even five years ago. The passing of the Infrastructure Investment and Jobs Act (IIJA) and the Inflation Reduction Act (IRA) acknowledged a changing world and priorities as well as how we disseminate funding to the states. While it didn’t offer a long-term fix to secure the Highway Trust Fund (HTF), it was perhaps a glimpse in a shifting philosophy. The use of grants to incentivize sustainability as a central White House objective was crafted in the highest offices of the Administration. As a result, since the implementation of IIJA, we’ve seen millions of dollars in the form of grants (as opposed to formula funding) make their way to state and local entities. On March 12, the Federal Highway Administration (FHWA) announced the availability of the Low-Carbon Transportation Materials (LCTM) grants to incentivize changes in materials selection. The goal is laudable, but in highway materials selection, states are not generally conditioned to think differently by way of applying for funding quickly or implementing objectives set forth by elected officials. Hence, the Reduced Carbon Concrete Consortium (RC3) was born. In this edition, you will see reference to RC3, a consortium and a resource for DOTs and other qualifying entities interested in LCTM funds. The RC3 was formed by engineering professionals and rounded out by the ACPA, the CP Tech Center and other professional paving engineering experts. The partnership was expanded to include the National Read Mix Concrete Association (NRMCA), the MIT Sustainability Hub and the Concrete Advancement Foundation (CAF). Together, all of this knowledge has disseminated information to DOTs and agencies across the country to help navigate the new frontier and capitalize on opportunities for their regions. We have developed templates to assist with the application process, and we are otherwise helping ensure that states don’t miss out because they may not understand the options. Summer Editorial The partners of RC3 have decades of experience and are available as a free resource to help ensure that policy passed in Washington, DC is implementable at the state and local level. Throughout the rounds of the LCTM, we will be directly assisting qualifying entities. We are here to address confusion. However, we recognize that the confusion is not solely at the agency level. At the heart of policy-related change are Environmental Product Declarations (EPDs)—those approved declarations explaining the life-cycle impacts of products. It is incumbent upon concrete paving contractors to understand and implement EPDs. It’s lofty, but not insurmountable and RC3 can help. Throughout the rest of the year, ACPA and its partners will be prioritizing its work with DOTs and contractors to improve understanding and implementation. Call on us as a resource. We are here. For more information, scan this QR code to be taken to the RC3 website. Having just completed a successful Mid-Year Meeting in Kansas City, we are already busy preparing for our Annual meeting, to be held December 3–5, 2024 in Phoenix, AZ. Laura O’Neill Kaumo President & CEO American Concrete Pavement Association Laura O’Neill Kaumo President & CEO American Concrete Pavement Association 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
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CONCRETE PAVEMENT PROGRESS 8 WWW.ACPA.ORG Introducing the ReducedCarbon Concrete Consortium (RC3) THIS SPRING, IN ANTICIPATION OF THE PENDING ANNOUNCEMENT RELATED TO STEPS IN RELEASING FUNDING FROM THE INFLATION REDUCTION ACT SECTION 60506 LOW- CARBON TRANSPORTATION MATERIALS GRANTS LCTM PROGRAM, ACPA, THE NATIONAL CONCRETE PAVEMENT TECHNOLOGY CENTER (CP TECH CENTER) AND OTHER QUALIFIED ENGINEERING PROFESSIONALS FORMED THE REDUCED CARBON CONCRETE CONSORTIUM (RC3). The purpose of the Consortium is to help disseminate information on reducing carbon in the construction process and assist DOTs and other qualifying entities with the LCTM application. RC3 is working with DOT representatives—as well as with contractors and cement and concrete partners—to support the application process and assist with critical next steps. The Consortium is also available to provide technical assistance to DOTs and facilitate contractor preparedness with critical next steps such as Environmental Product Declarations (EPDs). In addition to key leadership by ACPA, RC3 participants include the CP Tech Center, the Concrete Advancement Foundation, National Ready Mixed Concrete Association (NRMCA), MIT Concrete Sustainability Hub, as well as two key engineering consultants: Thomas J. Van Dam, PhD, P.E., FACI, LEED AP, Van Dam is a Principal at Wiss, Janney, Elstner (WJE); and Lawrence L. Sutter, PhD, P.E., FASTM, FACI, Principal, Sutter Engineering LLC. Initial applications were due June 10. In anticipation, the RC3 team has helped DOTs, owners, decisionmakers and contractors navigate lowcarbon funding opportunities and benchmarking requirements (i.e., EPD creation and application). Additionally, RC3 provides technical assistance on a variety of low-carbon technical factors including, but not limited to: • Specification consultation • Materials selection consultation • Workshop hosting • Program advisement • Technical engineer support For more information, visit http://rc3.acpa.org or contact ACPA’s Eric Ferrebee at eferrebee@ acpa.org. If you are a project owner, governmental entity, tribal government or other potentially qualifying grant recipient and need application assistance or technical support to achieve low-carbon concrete initiatives, contact Tom Van Dam at tvandam@wje.com. CARBON CONCRETE CONSORTIUM
WWW.ACPA.ORG 9 SUMMER // 2024 CARBON CONCRETE CONSORTIUM Traveling the Road to Carbon Neutrality » What are LCTM grants? The IRA created the LCTM grants program to reimburse and provide incentives to eligible recipients for using construction materials and products on projects that have substantially lower levels of greenhouse gas (GHG) emissions associated with production, use and disposal compared to estimated GHG emissions of similar materials or products, as defined by the EPA. The LCTM Grants Program is an opportunity for DOTs and other qualifying entities to not only reduce carbon but contribute to the improvement of concrete quality overall. A program supported through the LCTM grant can consist of multiple steps that will lead to substantial reduction of embodied carbon over time. » What materials are eligible? Eligible materials are concrete, asphalt, flat glass and steel with “substantially lower” global warming potential (GWP). “Substantially lower” values have been set by the EPA, based on national/regional industry data, and must be demonstrated through an Environmental Product Declaration (EPD). » What projects are eligible? Under this program, funds are available to use on construction projects funded under 23 U.S.C., including projects on: » Who can receive a grant? » How do I get started with LCTM applications? LCTM grants involve a two-part application process. State DOTs will be able to apply first, with 90 days to respond. Other eligible entities are able to apply next, with 90 days to respond. There is one application allowed per entity. » What can DOTs expect during the application process? DOTs prepare a plan or program to establish processes to pursue low-embodied GWP. Each agency submits a single application for their entire program, selecting which eligible materials they want to include—RC3 encourages applicants to include concrete. Programs should be broad and include all information needed to adopt LCTM in construction. This may include, but not limited to: » What costs does the grant cover? LCTM program grants cover all extra costs associated with using an eligible material including higher material costs but also costs associated with additional design, specifications, training and/or monitoring as covered in their approved Implementation Process Reports (IPRs), including the cost in developing the IPRs. » Where can I learn more and apply? The National Concrete Pavement Technology Center recently published the Guide for Reducing the Cradle-to-Gate Embodied Carbon Emissions of Paving Concrete, which provides agencies with strategies to reduce the environmental impacts of concrete production, as part of its FHWA Cooperative Agreement: Advancing Concrete Pavement Technology Solutions. Learn more about the publication and access the guide at: https://cptechcenter. org/news/cp-tech-center-publishes-reduced-carbon-guide. The request for applications can be found at https://www.fhwa.dot.gov/lowcarbon. » Federal-aid highway » Tribal transportation facility » Federal lands transportation facility » Federal lands access transportation facility » Federal-aid highway » Tribal transportation facility » Federal lands transportation facility » Federal lands access transportation facility » Specification review/modification » Adopting performance-based testing to ensure innovative new materials perform » Benchmarking current GHG emissions to assess improvement » Workforce development » Demonstration projects » Project implementation » Monitoring
CONCRETE PAVEMENT PROGRESS 10 WWW.ACPA.ORG ROUNDABOUTS Roundabouts: A Construction Curve Ball Eric Ferrebee, P.E., Senior Director of Technical Services, American Concrete Pavement Association A version of this article was authored by Eric Ferrebee, P.E., Senior Director of Technical Services, American Concrete Pavement Association and published in Modern Contractor Solutions magazine in May 2024. THE SLOWING AND TURNING OF TRAFFIC THROUGH A ROUNDABOUT, WHICH IS GREAT FOR TRAFFIC MANAGEMENT, CAN BE LESS THAN GREAT IN TERMS OF PAVEMENT WEAR. THIS MEANS PAVEMENT STRESSES ASSOCIATED WITH ROUNDABOUTS NEED TO BE ADDRESSED DURING DESIGN. As a rigid surface that is not prone to rutting or shoving, concrete pavement is well suited to handle the stresses and heavy loading inflicted on roundabouts. However, because of the challenging geometry of roundabouts and other intersections, specialized design and construction considerations come into play. The biggest consideration for concrete roundabouts is the spacing, type and layout of joints. All concrete pavement is jointed to control the location of cracks. Conventional concrete pavements can be jointed in a rectilinear pattern, but complex geometries of roundabouts and other intersections create a jointing challenge. For roundabouts, given their curvature and non-standard shapes, rectilinear jointing leads to odd-shaped slabs and does not guide drivers through the circular roadway. In addition to safety and constructability considerations, this can lead to improper load transfer and increased wear. Therefore, at the outset of design, engineers and contractors should adopt a jointing strategy and lay out a detailed joint plan. One strategy is to pave the circle separately from the incoming roads, or approach legs. This is known as the “isolated circle” approach. Another common method is to carry one of the incoming roadway’s pavements through the roundabout, leaving the remaining legs isolated. This is known as the “pave through” method. Both ensure joints in the circular portion radiate from the center and joints in the legs are normal or perpendicular to the edge of the pavement. When developing a detailed jointing plan, general rules are to: • Place joints to meet in-pavement structures. • Match existing joints or cracks, both location and type. • Calculate and abide by maximum joint spacing. • Place isolation joints where needed. • Cut joints at the proper time and to the proper depth. • Understand that joint locations can be adjusted in the field. Things to avoid include: • Slabs that are too small or too large. Slabs should be in the range of two to fifteen feet. • Angles that are less than sixty degrees; small angles encourage cracks to take a shorter or different path than the one intended with the saw cut. 90-degree angles are best. • Creating interior corners and odd-shaped slabs. Keep slabs nearly square or rectangular, when possible. Free tools, such as Wikipave and Pavement Designer.org, are available to walk designers through the steps of developing a jointing plan and pavement design. Pavement thickness is also a variable in roundabout construction. At-grade intersections of residential, collector and business roadways generally will not require any extra concrete thickness. Roundabout-area pavement thickness can be the same as the thicker of the two approaching roadways. For intersections involving roadways carrying high levels of trucks (such as with industrial and arterial roadways) the roundabout area may require as much as 0.5–1.0 in. (12–25 mm) of additional thickness. A design tool like PavementDesigner.org is recommended for determining the thickness for each roadway and calculating the combined traffic through the intersection. If additional thickness is warranted, it is pragmatic to apply the controlling thickness for the entire functional area of the roundabout including the approach legs. The transition from thinner roadways into a thicker intersection is generally best kept at a location before the radii for the intersection. A transition length of about 3–6 ft (1–2 m) for changing the thickness is usually adequate. The same materials and mix design specifications can be used for roundabouts that would be used on other concrete roadways, although it may be necessary to adjust the mix to accommodate placement method (i.e., slipform paving, fixed form with screed, hand-finished or pumped). Accommodating traffic, especially in urban areas, should also be considered during a roundabout’s design and planning stages. A phasing The roundabout in Overland Park, Kansas offers an excellent example of an isolated circle roundabout jointing plan. Joints were adjusted on the legs to accommodate the crosswalks.
WWW.ACPA.ORG 11 SUMMER // 2024 plan can determine how to maintain traffic flow during construction. Roundabouts generally require more phases than standard concrete paving, depending on the size of the roundabout (diameter), number of lanes in the circulating roadway and the style of design employed. While complete or partial closures are optimal from a cost and time perspective, if work needs to be performed under traffic, it is usual to perform work in the driving lanes of the major roadway before those of the crossroad. Concentrating on the major roadway pavement generally produces a smoother-riding intersection. One common method for constructing roundabouts while maintaining traffic is to create a temporary by-pass which allows the contactor to build the circular roadway without disruption. About the American Concrete Pavement Association: The American Concrete Pavement Association (ACPA) is the national trade association for the concrete pavement industry. ACPA’s mission is to develop and protect concrete pavement markets through education, advocacy, marketing and industry technical leadership. ACPA’s vision is for concrete to be the pavement material of choice, benefitting communities and society within U.S. state and local economies. 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. ROUNDABOUTS
CONCRETE PAVEMENT PROGRESS 12 WWW.ACPA.ORG DIAMOND GRINDING “Diamond Grinding: A Safe, Sustainable, Quiet and Cost-Effective Solution to Better Roadways”: Part One Diamond Grinding Offers Solutions to Many Pavement Challenges Highways have come a long way over the last 100 years. In generations past, the goal of roads was to keep people and goods moving to market and prevent vehicles from getting stuck in the mud of country roads. In the 21st century, the expectations and capabilities of highways have shifted. Today, users expect long-lasting, efficient, comfortable and safe passage from location to location. When evaluating pavements for surface characteristics, three of the most important considerations are sustainability, safety and comfort. There are many statistical realities that engineers can take advantage of when trying to achieve these goals. First implemented in the early 1960s, pavement diamond grinding is the process of stacking diamond saw blades next to each other on a machine-driven shaft. As this shaft spins, the diamond blades are lowered on to the surface of the pavement. They abrade the surface when they contact the pavement material, removing high spots in the road profile and leaving behind a superior surface texture. Diamond grinding is like using a belt sander to remove edges and knots from a wood plank. By making the surface smoother, the number of localized and continuous elevation changes in the pavement surface are reduced. Diamond grinding has many additional benefits, particularly related to carbon and cost savings, less vehicle wear and tear and increased safety. A Pavement that Lasts In a 2000 article by the FHWA, Enhancing Pavement Smoothness, data was evaluated showing that the smoother a pavement is, the longer it will last. This is the result of reduced frequency and severity of dynamic loads applied to the pavement surface. Highways typically are designed for 18-kip axel loads. When vehicles bounce due to a bump, the weight of the vehicle paired with the down force induced by gravity can result in an impact load more than 1.5 times the design capacity. When this increased loading continuously happens throughout the day, the structure of the pavement can experience significant fatigue. This premature breakdown of the pavement structure will cost owner agencies because they will not experience the expected lifespan of their investments. Similarly, the surface deterioration of these failing pavements will create cracks and potholes that pose a safety risk to the traveling public. The longer maintenance needs are left unattended, the more likely issues will expand—which can quickly increase the cost to repair. Surface damage that is fixed almost immediately may have negligible negative impact to users and modest repairs costs, but damage left for an extended period can propagate an area of structural damage, requiring a more expensive repair in the future. Transport Notes from the World Bank evaluated the relationship between maintenance timing and cost on South African highways. It was At World of Concrete 2024, the ACPA’s association partner, the International Grooving and Grinding Association (IGGA), launched a white paper titled “Diamond Grinding: A Safe, Sustainable, Quiet and Cost-Effective Solution to Better Roadways.” The paper is an important contribution to the industry’s knowledgebase because it highlights the gains to be made, both in terms of sustainability and cost savings, using proper pavement preservation and maintenance. It assembles research results, case studies and more demonstrating how agencies and engineers can achieve long-lasting, efficient, comfortable and safe travel on highways—while also meeting the challenges of sustainability, noise levels, urban head island effect and budget—through the use of pavement diamond grinding. Beginning with this issue of Pavement Progress, we bring you the entire white paper in a series of three installments.
WWW.ACPA.ORG 13 SUMMER // 2024 DIAMOND GRINDING determined that three years of maintenance neglect resulted in six times the repair cost. Five years of neglect resulted in up to eighteen times the repair cost. This relationship is due to the level of invasive work required to remediate a pavement section. For example, if a concrete pavement suffers from slab curling, the very cost-effective diamond grinding treatment can be performed using heaving machinery and minimal hand work. However, if that pavement is left to be beaten by dynamic loads for an extended period, the need for crack and full-depth repairs will be more prevalent—and drive-up costs. Reducing the International Roughness Index (IRI) before significant damage is done will mitigate this untimely wear and tear on pavements, resulting in a more efficient use of tax dollars and building materials. CASE STUDY: ASSET MANAGEMENT IN ARKANSAS The Arkansas Department of Transportation (ArDOT) collects data on interstates every year. Once data collection is complete, it is processed and a pavement condition index (PCI) summary is calculated, using a weighted average of four types of pavement metrics: environmental cracking, structural cracking, roughness and rutting. Conditions are assessed using FHWA threshold criteria for each 1/10-mile-long pavement section. The index is then used to assign a pavement condition rating, or “grade,” which describes the pavement condition of the state highway system as good, fair or poor. Pavement Preservation Efforts Maintain Rideability at a Competitive Cost Several sections of the pavement on I-40 in Arkansas are constructed of concrete, and a 4.3-mile section in Johnson County, constructed in 2002, provides one example of the advantages of pavement preservation. This portion of I-40 sees an average daily traffic (ADT) of 28,000 vehicles per day, with 36% of that traffic being trucks. The pavement is constructed of a 4-inch stone base, 4-inch treated permeable base and 12-inch jointed concrete pavement. The outside lane is 14 feet wide with an 8-foot asphalt shoulder. The cost of the 12-inch concrete pavement at the time of original construction was $24.15 per square yard in 2002 dollars, for a total of $9.4 million. At the time of construction, the pavement had an average international roughness index (IRI) of approximately 100 inches per mile. Pavement preservation was triggered in 2019 when an IRI of 112 was measured, since the department’s goal is to keep IRI measurements close to 100. No maintenance had been performed on the pavement since it was built; the only maintenance activities had been periodic asphalt shoulder patching and cleaning of edge drains. In 2020, the department performed the concrete pavement preservation (CPP) work. The existing pavement was in excellent structural condition with very few cracked slabs, so CPP consisted of patching 138 square yards—or 0.1% of the area— along with diamond grinding for smoothness and joint rehabilitation. The project was ground to an average IRI of 43 inches per mile. The cost for diamond grinding was $825,000 and the cost for joint resealing was approximately $300,000. The total cost for the project was $1.125 million, or $65,400 per lane mile. Based on the positive outcome of the original concrete construction, combined with diamond grinding and other minimal CPP at the 15- to 18-year point, ArDOT integrated additional diamond grinding and CPP into its road management efforts, notably planning their use on two large sections on I-30. Save on Fuel With more attention than ever being focused on energy conservation, vehicle fuel efficiency and new alternatives such as hybrid cars and biodiesel, few people realize the significant impact that road rehabilitation methods like diamond grinding can have on energy use. Research by the MIT Concrete Sustainability Hub concluded that roughness and deflection of pavements impact the fuel economy of vehicles that traverse the pavement. When the surface of a pavement is smooth, vehicles traverse it more efficiently, with more of the expelled energy dedicated to forward movement rather than fighting vertical bouncing movements. When highway maintenance crews reduce the IRI of a pavement by 40%, it saves truck operators about .002 gallons of diesel or about .7 cents per truck per mile, according to IGGA’s Fuel/ Carbon Savings Calculator. While this figure seems negligible, it has a significant impact when entire highway sections are evaluated. Even when considering alternative fuel vehicles, such as electric vehicles (EV), it is important to recognize that the battery of an EV traveling on a smooth, diamond ground pavement will carry the vehicle for a longer distance because it can move more efficiently. Although at this time research has not been done to show exactly how much improvement takes place, MIT researchers suggest the expected increased distance would be the same as the percent of fuel saved for their gasoline-powered counterpart. By removing faulting, slab warping, studded tire wear and unevenness resulting from patches, diamond grinding creates a smooth, uniform pavement profile. The longitudinal texture continues on page 14 »
CONCRETE PAVEMENT PROGRESS 14 WWW.ACPA.ORG created by diamond grinding also enhances macro texture and skid resistance in polished pavements. DIAMOND GRINDING USES FEWER RESOURCES Research shows a correlation between rough pavements and reduced driving speeds, which can lead to congestion. Pavement congestion can increase drive times and idle time on highways, resulting in higher fuel consumption. Smooth pavements can help increase driving speed thus reducing roadway congestion. The nature of diamond grinding makes it one of the most efficient pavement preservation techniques. It can be completed in short lane closures for less time than typical asphalt overlays and may even be performed in a rolling closure next to live traffic. Overlays require the mining, producing and hauling of virgin material. Each one of these steps has a significant cost and carbon impact to the project. Comparatively, a diamond grinding project only requires the removal of a small amount of material from the jobsite in the form of slurry. It is also important to consider the life-cycle cost of paving and rehabilitating both types of pavement surfaces. An asphalt surface should be replaced approximately 8 to 15 years into its life with a new layer of asphalt. In that time frame and given the material hauling parameters, it is unlikely that asphalt overlays have the opportunity to be cost or carbon neutral. Diamond grinding on concrete pavements can last decades before requiring remediation. Pair this with the aforementioned material mining and hauling benefit, as well as the re-opening of concrete surfaces for carbon sequestration, and cost carbon neutrality becomes commonplace for diamond grinding. Highways with heavy traffic can even show a net negative cost and carbon impact. Safer Surfaces Highway users are constantly at risk of motor vehicle accidents. Rough pavements increase this risk because they can cause the suspension of the vehicle to bounce. In extreme instances, this can result in tires leaving the surface of the pavement, causing them to momentarily lose friction. Potholes also can jolt the steering mechanism of a vehicle, causing the operator to lose control. Proactive drivers may even swerve to continued from page 13 avoid potholes, causing them to depart from their driving lane and increasing the risk of contact with vehicles in adjacent lanes. Surface irregularities may impact drainage during wet weather events, increasing the risk of hydroplaning. Additionally, aggregates (rocks) dislodge and ravel out of an asphalt rubber overlay as it ages. These loose rocks lay on the pavement, acting like marbles on the roadway surface and reducing the braking ability of tires. This raveling of the pavement is also the reason the asphalt rubber gets louder over time. The University of Maryland compiled data from the United States, Australia and New Zealand. The results suggested a linear correlation between pavement roughness and vehicle accidents. The document also noted that pavements with ten millimeters (mm) of rutting showed a higher risk and higher severity of vehicle accidents. Concrete pavement preservation (CPP) with diamond grinding is proven to be safer, with 42% fewer accidents in all-weather conditions when compared to a tined pavement surface. And construction required to perform diamond grinding is a safer alternative as well. Diamond grinding can be constructed all year long in day and night shifts without closing the freeway. This allows for construction at times that least impact the consumer, unlike asphalt rubber, which can only be placed during certain times of the year. Diamond grinding significantly reduces the amount of traffic congestion and consumer delays during construction as well, which results in far fewer accidents. DIAMOND GRINDING
WWW.ACPA.ORG 15 SUMMER // 2024 SAFE SURFACES REDUCE VEHICLE MAINTENANCE The FHWA recognizes that smooth pavements reduce the need for maintenance on vehicle suspension and tires. Research cited in the Journal of the South African Institute of Civil Engineering concluded that in 2004, California drivers using roads in disrepair paid an average of $700 in vehicle maintenance and replacement cost compared to a national average of $400. The 43% increase in repairs to vehicles associated with road roughness was coined “the hidden tax of California road users.” These costs are significantly more when applied to commercial trucking equipment compared to passenger vehicles. This same function also translates to the goods being transported, as rough roads impact the condition of products before hitting store shelves. Tests have shown that roughness, as measured by the IRI, grows faster on asphalt versus concrete and asphalt will be rougher at twenty years old. Concrete pavement experiences a much slower deterioration and can take decades to reach the same condition level. Mill and fill must be performed on asphalt pavement about every ten years to keep roughness under control; even then, it experiences periods of poor condition compared to concrete, which can be diamond ground every twenty-five years and remain fairly smooth. Because CPP-treated pavements stay smoother, they provide a quieter, better ride for motorists as well. Lower Roadway Noise Rough pavements and transversely tined pavements have a higher decibel reading compared to smooth and longitudinally ground pavements. According to the FHWA, highway noise is typically 70 to 80 dB(A) when standing fifty feet from the highway. Sounds in excess of 80 dB(A) can cause hearing damage after extended exposure. The World Health Organization (WHO) attributes excess noise pollution to social, physical and mental health issues. Highways that run through urban areas can make it difficult for people to carry on conversations and interrupt concentration, having a negative social impact. Excess background noise has been shown to increase heart rate as well as increase potential for mental health episodes, creating an increased risk of physical harm, according to the WHO. Typical building codes for noise in the United States requires 45 to 55 dB(A) in living spaces during the day. This means that highway noise in urban areas must be kept at manageable levels to allow developers to build livable communities near highways. CASE STUDY: CALIFORNIA STATE ROUTE 85 TESTED FOR QUIETEST PAVEMENT Route 85 near San Jose, Calif., has a high level of traffic—and noise is a major concern for local residents. With a truck ban in effect for Route 85, the main traffic noise source is from the interaction between passenger vehicle tires and the pavement surface. Parts of Route 85 are depressed and there are sound walls along the roadway. Previous noise studies have indicated that raising the height of the existing sound walls would not be effective in further reducing the noise levels. In response to these issues and complaints from the local citizens, a .88-mile diamond grinding test section was constructed between DeAnza Blvd. and Saratoga Ave. The citizens responded favorably to the test section. In June 2005, Caltrans contracted with Illingworth and Rodkin, Inc., to conduct tire pavement noise evaluations of the existing longitudinal tined surface and the diamond ground texture. The tire pavement noise evaluations found the diamond ground surface was almost 2.5 dB(A) lower in overall noise level and exhibited significantly less variability. The frequency content of the diamond ground texture was superior to all others, particularly in the 800- to 1,250-hertz range where human hearing is particularly sensitive to these frequencies. According to the Valley Transit Authority (VTA) project report, “diamond grinding caused a downward shift in the tonal characteristics of the sound and decibel reductions at frequencies that are easily heard by human ears.” The public responded favorably to the test section and, as a result, the VTA constructed a full-scale diamond grinding and grooving project on Route 85 between I-280 and Highway 87 in 2005. The goal of the project was to remove the roadway’s existing surface texture that was creating the offending sound. For the safety of the public and construction workers, traffic control measures including temporary lane closures and detours were used when needed. The cost of the project, which began in mid-2005 and was completed in mid-2006, was nine million dollars. The result for the citizens who had complained of noise from the highway before the changes is a quiet highway that has significant reduction in decibels and improvement in tonal qualities. The result for taxpayers is a low-noise highway surface that will last for the next fifteen years or more. Part 2 of IGGA’s white paper will be published in ACPA Pavement Progress’ Fall 2024 issue. Stay tuned! DIAMOND GRINDING
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WWW.ACPA.ORG 17 SUMMER // 2024 100-YEAR-OLD HIGHWAY 100-Year-Old Highway Shows a Legacy of Durability and Smart Investment SOUTH DAKOTA’S FIRST CONCRETE HIGHWAY TURNED 100 YEARS OLD LAST YEAR, AND IT IS STILL STANDING STRONG. The highway in Sioux Falls, South Dakota, was constructed in 1923 and is a testament to the longevity and reliability of concrete. In 1922, South Dakota embarked on constructing its first concrete highway, which still serves its purpose effectively 100 years later. The highway was a project initiated by the South Dakota Department of Transportation, known at the time as the Bureau of Public Roads. The construction started in Sioux Falls and extended to Dell Rapids. The highway’s design included a width of 18 feet, with expansions up to 25 feet at curves to accommodate traffic efficiently. This road was part of the intended King of Trails Highway, connecting Winnipeg, Canada, to the Gulf of Mexico. Interesting twists in history saw the highway rerouted twelve years post-construction to accommodate the building of a new railway bridge. Today, four-hundred feet of the original pavement still exists, accommodating parking for the South Dakota State Penitentiary to the north and serving as the driveway to the Iglesia de Jesucristo Church to the south. Despite the changing plans and rerouting, a significant part of this robust concrete structure has survived, demanding minimal maintenance and never undergoing overlay. Potholes and cracks were filled using an asphalt-like substance as joints were not sawed into the original pavement. Constructed using a straightforward 1:2:4 concrete mix comprising one-part cement powder, two parts sand and four parts rock, the highway sustained the harsh South Dakota summers and the icy winters with numerous freeze-thaw cycles annually. Concrete pavement was selected to help withstand heavy I-5 traffic and California’s hot temperatures. The endurance of this highway and the economical decision to allow its continued existence is a testament to the excellent foresight of the state authorities. Today, a nearby greenspace displays a plaque commemorating the road as the first concrete state highway in South Dakota and a historic engineering landmark, as recognized by the American Society of Civil Engineers. Last year, the highway was celebrated as it reached its centennial mark. Jason Reaves, the Executive Director for the South Dakota Chapter of the American Concrete Pavement Association (ACPA), was among the group of state and local officials marking the road’s hundredth birthday. This road signifies the enduring nature of concrete, portraying it as an economical choice for paving with a lifespan exceeding a century, far surpassing its expected longevity. Therefore, putting money into concrete paving means investing in the future of road infrastructure. The longevity of the pavement has saved taxpayer dollars, reduced maintenance costs and served as a repurposed roadway. Although the highway no longer serves as a fundamental thoroughfare, Sioux Falls takes immense pride in being home to the state’s first paved roadway.
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WWW.ACPA.ORG 19 SUMMER // 2024 ACPA NEWS
CONCRETE PAVEMENT PROGRESS 20 WWW.ACPA.ORG Advertiser Index American Engineering Testing www.teamaet.com 9 APR Consultants, Inc. www.aprconsultants.com 11 Ash Grove Cement Co. www.ashgrove.com 11 Astec Industries www.astecindustries.com 7 CMT Technical Services www.cesareinc.com 19 Continental Cement www.continentalcement.com 18 Crafco, Inc. www.crafco.com 6 E2 Systems, LLC www.materialplacer.com 7 Erie Strayer Company www.eriestrayer.com 1 Flores Automation www.floresautomation.com 16 GOMACO Corporation www.gomaco.com Back Cover Heidelberg Materials www.heidelbergmaterials.us Inside Back Cover Holcim www.holcim.com 18 Minnich Manufacturing www.minnich-mfg.com 5 Power Curbers www.powercurbers.com Inside Front Cover Pugmill Systems, Inc. www.pugmillsystems.com 19 Shumaker Industries www.shumakerindustries.com 16 Wirtgen America, Inc. www.wirtgen-group.com 2 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 $360! • Discounted ACPA Member Rate • ADVERTISER I N D E X
American Concrete Pavement Association 9450 Bryn Mawr Ave., Ste. 150 Rosemont, IL 60018 THE OFFICIAL PUBLICATION OF THE AMERICAN CONCRETE PAVEMENT ASSOCIATION / ACPA.ORG PAVEMENT PROGRESS SUMMER // 2024
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