Transverse joints are the weakest link in the performance of concrete pavement structures. Joints can rely on aggregate interlock for transferring load from one panel to the next. However, higher volumes of traffic or the presence of weak underlying soils necessitates the inclusion of some type of load transfer device such as dowel bars or other devices. It is desirable to identify new and innovative concrete pavement joint systems that give high performance with lower initial construction cost. One such system, JOINTS JRI+, consists of a patented joint insert that is claimed to provide high performance concrete pavement joints with low initial cost. Many other innovations in transverse joint design are available including: . Undoweled joints with structural fibers in the PCC mix . Fiber reinforced polymer (FRP) dowel bars . Oval section dowel bars . Hollow tube dowel bars . Epoxy coated dowel bars . Stainless clad dowels . Large diameter (1 ¾ inch) dowel bars . Soft saw-cutting This pooled fund study will seek substantial industry involvement. For a 500-ft test section with 15-ft joint spacing, there are about 33 joints per lane per test section. It is anticipated that five different products (from those previously mentioned or others) will be installed, which amounts to six joints per lane per test section for each product. The manufacturer of each product will be asked to deliver and install their joint design system during the construction process. This proposed research is in harmony with Track 6 of the CPTP Road Map. This track address proposed research that will help develop breakthrough technologies and extremely high-speed joint repair techniques. One issue that could be examined in this study is the process for repairing the joints if they eventually fail. Each joint system may present unique challenges for maintenance or rehabilitation in the future. Related studies include: . TPF-5(066): Material and Construction Optimization for Prevention of Premature Pavement Distress in PCC Pavements (Iowa) . NCHRP 10-69: Guidelines for Dowel Alignment in Concrete Pavements (University of Minnesota) . NCHRP 10-37A: Performance of Epoxy-Coated Reinforcing Steel ¿ Laboratory Testing (Florida Atlantic University) . NCHRP 20-50: LTPP Data Analysis: Relative Performance of Jointed Plain Concrete Pavements with Sealed and Unsealed Joints (Kathleen T. Hall) This project has the potential to examine several different innovative systems for managing transverse joints in concrete pavements. In Minnesota and many areas around the country, concrete pavements fail at the joints before they fail structurally under heavy loads. Efficient joint systems will achieve load transfer across the joints as well as reduce stresses in the pavement slabs. The amount of subgrade support under the joint also affects its performance. There is the opportunity to study different levels of subgrade support in this study. Many alternatives exist on the market for joint design of concrete pavements. This study provides an opportunity to perform a side-by-side comparison of several products to determine their efficiency and performance. The results of this study will provide information for partnering states to modify their specifications for transverse joint design. MnROAD provides a unique opportunity to study pavements with known traffic applications and weather conditions in a safe and controlled work environment. The ability to divert traffic allows researchers to monitor and sample test sections in a safe manner, and it encourages researchers to push the envelope and try something new without causing a major disruption to the traveling public if it fails prematurely.

The objective of this research is to demonstrate the performance of one or more concrete pavements utilizing several innovative joint systems. Through instrumentation and performance monitoring, it could be determined whether these joint systems are suitable for a wet-freeze climate and traffic loadings. To accelerate the potential distress of the system, several concrete test sections would be constructed on the mainline and low volume roads at the Minnesota Road Research Facility (MnROAD). To further the understanding of the potential long-term performance of the joint systems, several slabs containing the joint systems could be tested on the Minne-ALF 2, (http://www.pri.umn.edu/resources/minnealf/index.html), Heavy Vehicle Simulator (HVS), or other accelerated pavement test facilities. This pooled fund study is strictly to perform the joint system research on newly built concrete test sections at MnROAD, and its funding will come from Mn/DOT and other participating states. The funding for initial construction of the test sections will be obtained separately from Mn/DOT and other partners.

This project is expected to consist of the following activities: . Work Plan: The work plan for this pooled fund study will be developed by the participating organizations. This will include the selection of joint design systems to be used in this study. The companies or associations that design and manufacturer the joint systems would be asked to donate the joint forming materials. . Instrumentation Design: Thermocouples, strain gages, clip gages, etc. . General Testing & Monitoring: Monitor the pavement performance over this time on each of the sections. Monitoring activities will include distress surveys, ride measurements, friction, faulting, and analysis of pavement sensor data. . Special Testing & Monitoring: Evaluate the load transfer and other performance measures across each joint in the concrete pavement. The testing and monitoring activities will compare the different joint systems. . Pooled Fund Travel: Money for each state to travel to discuss the progress of the study. . Data Analysis & Report: Work done under a research contract will develop interim and final reports that document the findings of this study.

Mn/DOT along with other participating states are asked to contribute $15,000 per year for 5 years to fund the research proposed in this pooled fund study. The Minnesota Department of Transportation (as the lead agency) along with other partners will provide approximately $200,000 in initial construction funding outside of this pooled fund study to construct the pavement sections.