NCC E-News in association with the CP Road Map Program
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. For the JULY 2019 E-News, please click on image to the right, click on the link under each article description below, or go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
Moving Advancements into Practice (MAP) Brief: MAP briefs describe promising research and technologies that can be used now to enhance concrete paving practices. The July 2019 MAP Brief, “Optimized Joint Spacing for Concrete Overlays with and without Structural Fiber Reinforcement”, summarizes field research in Iowa on optimized joint spacing, showing that thicker overlays (with or without fibers) exhibited increased percentages of joint activation. Also, the ratio of slab length to radius of relative stiffness appears to be a good indicator for joint activation behavior and can be used to help optimize joint spacing design for concrete overlays. To download the PDF of the 12-page JULY 2019 MAP Brief, please click on image to the left, or go to: http://www.cproadmap.org/publications/MAPbriefJuly2019.pdf
NCC State Survey
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.
The Missouri Department of Transportation polled the NCC group regarding limits placed on the number of lanes that can be tied (19 states responded) and the use of pull-out tests for lane ties (23 agencies responded). … to read this article and download documents, please go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
News from the Road:
Highlights research around the country that is helping the concrete pavement community meet the research objectives outlined in the CP Road Map. The research projects and the summaries described herein are the products of the researchers and sponsors.
Premature Failure of Concrete Patching: Reasons and Resolutions (report date: March 2018): The performance of concrete patches in continuously reinforced concrete (CRC) pavement in Virginia varies from less than one year to many years. The purpose of this study was to determine the causes of premature repair failure in continuously reinforced concrete pavement. Four pavement sections were monitored for patching operations. Mixture designs had high cementitious material contents. The patches were typically constructed with a short lane-closure time, often at night, with only about five to eight hours of cure time before opening of the roadway to traffic … to read this article and download documents, please go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
Practices in One-Lane Traffic Control on a Two-Lane Rural Highway: Temporary traffic control, also known as maintenance of traffic, is critical to minimizing congestion and maintaining mobility during planned and unplanned activities as well as providing a safe work zone for both road users and workers. This synthesis identifies innovative practices and devices for establishing one-lane traffic control on rural two-lane highways. A literature review and detailed survey responses from 45 (of 50) departments of transportation (90% response rate) are presented … to read this article and download documents, please go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
Accelerated Testing of Full-Scale Thin Bonded Concrete Overlay of Asphalt: A research study was conducted with the goal of determining the expected performance life of 4-in. to 7-in. thin bonded concrete overlay of asphalt (BCOA) in California. Eleven thin BCOA sections were built and tested with the Heavy Vehicle Simulators (HVS) in Davis, California. The performance of the sections in the HVS testing provided insight into the mechanics of the thin BCOA structures and the effects the different rapid-strength concrete materials, traffic, jointing, and base factors on their performance, including testing in both very wet and very dry conditions. Overall, the performance of the thin BCOA sections in the HVS testing was excellent … to read this article and download documents, please go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
Curing Concrete Paving Mixtures: Proper curing of a newly placed concrete pavement is an essential step to ensure that the concrete as designed, batched, and placed reaches its full potential. Improper curing can result in inadequate hydration and reduced concrete strength and can negatively affect the near surface concrete properties including increased permeability, decreased wear resistance, and increased risk of plastic shrinkage cracking. This Tech Brief focuses specifically on approaches commonly used for curing cast-in-place concrete pavements … to read this article and download documents, please go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
An Assessment of the Models to Predict Pavement Performance: Data collected by the Iowa Department of Transportation (DOT) regarding road conditions across the state of Iowa were used to model pavement condition index (PCI). The data were for calendar year 2013, with updated PCI values and indicators of the resurfacing of road segments from 2014 to 2015. The data file provided by the Iowa DOT consisted of nearly 4,000 observations. 18 different road conditions and measures were considered as possible model inputs: 11 were used in the final prediction of PCI in 2014 and 2015 for portland cement, composite, and asphalt cement pavement types. These measures included International Roughness Index (IRI), friction value, age, average daily traffic, PCI value in 2013, number of lanes, daily temperature change, surface type, pavement thickness, speed limit, and reconstructed kips … to read this article and download documents, please go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
Evaluation of Concrete and Mortars for Partial Depth Repairs: Partial-depth patching mixes must rapidly gain strength to allow the roadway to be reopened to traffic quickly. A patch should also bond well to the substrate to prevent the patch from separating from the existing material and be durable enough to withstand harsh winters. The objective of the research described in this report is to develop improved guidelines for evaluation of pre-bagged commercial patching mixtures and to recommend effective construction practices. To achieve these objectives, 13 different cementitious materials were selected and tested to determine key properties including strength gain, shrinkage, bond strength, and durability … to read this article and download documents, please go to: http://www.cproadmap.org/publications/e-news_Jul2019.cfm#MAP
If you’d like to find out more about the CP Road Map or learn how you can get involved, contact:
Dale Harrington, HCE Services
E-mail: dharrington@hceservices.com | P: 515-964-2020
Sabrina Shields-Cook, Editor | E-mail: shieldsc@iastate.edu
If you’d like to find out more about the CP Road Map or learn how you can get involved, contact Dale Harrington, dharrington@hceservices.com, 515-290-4014. Visit the e-news homepage for more details.