Report Offers Insights into SPS-2 Concrete Pavements
- Friday, 10 February 2017 17:59
The Long Term Pavement Performance (LTPP) SPS-2 study, or Strategic Study of Structural Factors for Rigid Pavements, represents the most comprehensive set of concrete pavement performance data in the United States, according to a report by Larry Scofield, P.E., IGGA/ACPA. Scofield has been studying and evaluating the SPS-2 pavements, and has prepared a brief report that shows some interesting details about the pavements that comprise the LTPP test sections.
Map show states constructing SPS-2 projects (and year of construction). The pavement design features evaluated are: concrete thickness (8” and 11”); base type; flexural strength; lane width, and drainage.
Scofield reports the SPS-2 experiment consists of 12 LTPP test sections constructed in each of 14 states ranging in age from 15 to 23 years (2015), with the first project constructed in Kansas in 1992. The original experimental design for the SPS-2 experiment consisted of 192 test section, but only 120 (63%) were constructed. This will hinder future statistical analysis to some degree.
Four states constructed replicated sections of the original design, thereby producing 48 additional test sections. Of these, three states are in the wet-freeze zone and one state is in the dry-freeze zone. This resulted in a total of 168 SPS-2 test sections. In addition, 40 state supplemental sections were constructed and evaluated for a total of 208 sections.
- Of the original 144 SPS-2 core test sections constructed, 83% (119) of the test sections are still in service after 16 to 24 years of traffic.
- Of the original 40 SPS-2 State Supplemental test sections constructed, 90% of them are still in service after 16 to 24 years of traffic.
- Of all the SPS-2 test sections constructed (core and supplemental) 84% are still in service after carrying traffic for 16 to 24 years.
- The SPS-2 experiment has a higher percentage of surviving sections than any other SPS project.
- Since 84% of the SPS-2 test sections are still in service after 16 to 24 years of traffic, the experiment has outperformed all other LTPP experiments, providing evidence of concrete pavement’s long-life characteristics and the potential to sustain heavier axle loads than currently designed for.
Showcase Focuses on Two-Lift Concrete Pavements
- Friday, 10 February 2017 14:47
Showcase participants had the opportunity to visit the two-lift concrete pavement construction site. (Photo: ACPA.)
As part of the second Strategic Highway Research Program (SHRP2) program’s Project R21, a technology showcase was held on January 31 in Burbank, Calif. The focus of the showcase was two-lift concrete pavement construction, and the event drew roughly 70 people representing industry and the public sector.
As a lead state for implementation of SHRP2 R21 technologies, Caltrans, along with Federal Highway Administration, co-sponsored the showcase. The event began with a technical program featuring several agencies’ experience with two-lift concrete paving (including Caltrans, the Illinois Tollway, Minnesota DOT, Tennessee DOT, Texas DOT, and Virginia DOT), followed by a field visit to an ongoing two-lift paving project on Interstate 210 near Montrose, CA. Leif Wathne, ACPA Executive Vice President, was on hand for the event and provided insights on the technology during the discussions.
The project involves a 12-in. thick jointed-plain concrete pavement comprised of a 8-in. bottom lift and a 4-in. top lift. The bottom lift features two separate concrete mixtures, one with reduced cement content and one with recycled concrete aggregate.
About Project R21
Project R21 involves the development of design and construction guidelines for new composite pavement systems, including concrete pavements placed in two-lifts using a wet-on-wet process. Two-lift concrete pavements are said to provide significant potential benefits, including improved surface characteristics, reduced agency costs, lower energy costs, and reduced environmental impacts
ACPA to Participate in Trade Delegation Program
- Wednesday, 08 February 2017 18:28
ACPA will participate in a Special American Business Internship Training (SABIT) program on highway and roadway construction later this month.
ACPA Executive Vice President Leif Wathne will make a one-hour presentation on concrete pavements to a delegation of approximately 20 officials representing road-building interests in Azerbaijan, Georgia, Kazakhstan, Kyrgyz, Moldova, Russia, Tajikistan, Turkmenistan, and Ukraine.
This program is aimed at providing training to mid- and senior-level industry and State officials who are involved in highway and roadway construction in the Commonwealth of Independent States and Georgia.
ACPA has participated in similar programs on three occasions since 2007. In addition to being a good technology transfer opportunity, the program also allows ACPA to cite member companies involved in technology development and product sales in global markets.
Annual Meeting Spotlights Technology Transfer
- Wednesday, 14 September 2016 18:29
One of the highlights of ACPA’s annual meeting is the annual Concrete Pavement University technology transfer event, which features project stories, research results, best practices, and other information intended to improve quality and save money. Organized by date and time—and presented with other events of the days—here is a snapshot of our program:
Wednesday, November 30
- CPU Opening Session—What do a project story in Texas, a high-tech grade assessment, a paving project at a Microsoft facility, and the analysis of the first concrete pavement in the United States all have in common? The answer is they’ll all be in the spotlight for our exciting and informative CPU opening session.
- (Lunch) Special Guest Speaker—You won’t want to miss our lunchtime guest speaker, Mike Robertson, who will entertain, inspire, and dazzle audiences with humor and storytelling.
- Annual Membership Meeting—Before we continue with our CPU program, please join us for our annual membership meeting…but be prepared for some surprises (and a laugh or two).
- CPU Special Technical Session—We’re back to our CPU programa with this special track that cover performance specification and pay factors. Learn about the latest in performance-based specs and contractors’ experiences with projects using PaveSpec.
Thursday, December 1
- (Breakfast) Keynote Speaker—You will not want to miss the ACPA Legislative Issues Task Force’s special guest, James M. Bass, Executive Director, Texas Department of Transportation. He will provide a perspective on highway funding and instilling competition between industries in the Lone Star State.
- CPU Breakout Track 1–Future Technology Today is the theme of this track, which will cover Greenroads and Concrete Pavements; an explanation of recycling waste carbon dioxide to lower the concrete footprint, and a discussion of the Athena pavement LCA.
- CPU Breakout Track 2–Take a new look at traditional materials with this track, which will feature a new look at ASTM C94, a candid talk about fly ash, and a presentation on the flexibility of using slag.
- CPU Breakout Track 3–Pavement smoothness perspectives for contractors is the focus of this track, which will include a presentation on North Dakota’s ultra-smooth IRI specification; how to use ProVAL to reduce must-grinds and increase profits; and the results of a curling and warping study.
- CPU Breakout Track 4–The very popular topic of curing and sealing innovations is the focus for this session, which will include a presentation on penetrating sealer to prevent joint deterioration; impacts of curing methods on curling; and the latest science in internal curing.
- CPU Breakout Track 5–Advancements in continuously-reinforced concrete pavements (CRCP) are in the spotlight for this session. Presentations will focus on CRCP-Texas-style; CRCP innovations; and reinforcement corrosion considerations.
- CPU Breakout Track 6–This concurrent session will focus on performance-engineered mixes and a new AASHTO Provisional Standards that will be a game changer for contractors. We’ll start off the session with some presentations, then follow with a panel discussion with leading experts.
- CPU Breakout 7 –Our final track will focus on pavement repair materials and related innovations. The session will include a contractor’s view of proper techniques for full- and partial-depth patching, followed by a panel discussion on the latest technologies and materials for performing these repairs. Materials and systems manufacturers will be on hand to discuss developments and answer questions.
Concrete Pavement University is just one of the many highlights of the upcoming 53rd Annual Meeting, scheduled for November 29 through December 1. Be sure to see the full slate of events … and to make your reservations as soon as possible. Click here for our one-stop hotel and event registration site for the ACPA 53rd Annual Meeting.