The NCC E-News is the newsletter of the Long-Term Plan for Concrete Pavement Research and Technology (CP Road Map), a national research plan developed and jointly implemented by the concrete pavement stakeholder community.
Moving Advancements into Practice (MAP) Brief: MAP Briefs describe promising research and technologies that can be used now to enhance concrete paving practices. The April 2017 MAP Brief, Performance Engineered Concrete Pavement Mixtures, explains the process of designing concrete mixtures to provide the performance properties desired rather than just using a “recipe” mix. To read the full 10-page PDF of the April 2017 MAP Brief, please click on image to the right, or go to: http://www.cproadmap.org/publications/MAPbriefApril2017.pdf
NCC State Survey Summaries: Member states of the National Concrete Consortium (NCC) have the ability to poll other member states regarding specifications, materials, construction, research, or other issues related to concrete paving. This section highlights some of the questions posed and answers received through the NCC’s ListServ feature.
Agencies’ Use of Keyways to Tie Multiple Lanes Together: The Minnesota Department of Transportation (MnDOT) polled the NCC group regarding the use of keyways when tying multiple lanes together. Twenty-six agencies responded. A vast majority (22) of the agencies responded that they do not typically use keyways between lanes. Several agencies cited a tendency to shear off or fail over time as a reason. Of the four that do currently use keyways, two indicated that they are looking to eliminate them.
News from the Road highlights research around the U.S. that is helping the concrete pavement community meet the research objectives outlined in the CP Road Map. To read E-news, articles, documents, and Tracks of the CP Road MAPs, click on the image to the left, or the links below each subhead below.
Lightweight Concrete for Reducing Bridge Deck Cracking: The Virginia Department of Transportation (VDOT) has been constructing bridge decks with lightweight concrete (LWC) for a number of years. VDOT recently constructed several bridges with LWC to examine the potential benefits that LWC may provide in reducing bridge deck cracking. Unlike most projects that replace a portion of the fine aggregate with water-saturated lightweight fine aggregate to provide internal curing, the VDOT utilized lightweight coarse aggregate. To read article, document, and Track 1 CP Road MAP, please go to: http://www.cproadmap.org/publications/e-news_April2017.cfm.
Evaluating Bond Strength Between PCC and Asphalt Layers: The bond between pavement layers in a composite pavement is an important factor in the performance of the pavement. For bonded concrete overlays of asphalt, this bond contributes to the overall structural capacity of the pavement. … The purpose of this research was to investigate a new test method to evaluate the bond strength between PCC and asphalt under tensile, shear, and combination tensile/shear loads at different temperatures (-4°F and +68°F). To read the entire article, document, and Track 8 Road MAP, please go to: http://www.cproadmap.org/publications/e-news_April2017.cfm.
Investigation of Roller Compacted Concrete (RCC) in Virginia: The VDOT investigated the properties and potential benefits of RCC. The project prepared laboratory mixtures utilizing locally available materials. Based upon this research, special provisions were developed and two field projects were constructed. The research found that the compressive strength, tensile strength, modulus of rupture, and modulus of elasticity for RCC were similar to conventional concrete.
There was some concern that fly ash, which is used in conventional concrete to improve durability, could cause a delay in early strength gain…To read the article, document, and Track 8 Road MAP, please go to: http://www.cproadmap.org/publications/e-news_April2017.cfm.
Comparison of Slab Stabilization Using Cementitious Grout and Polyurethane Foam: This research paper compares the in situ test results of injected polyurethane foam and cementitious grout for stabilizing deteriorating concrete pavements supported on an open-graded aggregate subbase. The stabilization was performed to improve support conditions by filling voids, reducing deflections, and improving load transfer efficiency (LTE) near joints and cracks. Falling weight deflectometer (FWD) tests were performed before and after stabilization. To read the article, document, and Track 7 Road MAP, please go to: http://www.cproadmap.org/publications/e-news_April2017.cfm.
To read the April 2017 NCC / CP Road MAP E-News, please go to: http://www.cproadmap.org/publications/e-news_April2017.cfm
To learn more about the CP Road Map or learn how you can get involved, please contact:
Steve Klocke, Snyder & Associates Program Manager:
E-mail: sklocke@snyder-associates.com
Dale Harrington, Snyder & Associates Program Manager:
E-mail: dharrington@snyder-associates.com
Sabrina-Shields Cook, Editor: E-mail: shieldsc@iastate.edu
Marcia Brink, Managing Editor: E-mail: mbrink@iastate.edu
Phone: 515.964.2020