ROSAN CRADA:
A Joint Effort to Improve the Nation's Highways
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| At the CRADA signing are (seated) R&D Associate Administrator Bob Betsold, SES President Scott Clements, (standing) FHWA's Dennis Sixbey, Roy Trent, SES's James Mekemson, and Nicholas Gagarin. |
When it comes to improving our Nation's highways, joining forces with the private sector is a clever way to go, and that is exactly what the Pavement Surface Analysis Lab did. On October 20, the Offices of R&D and Surfan Engineering and Software, Inc. (SES) signed a cooperative research and development agreement (CRADA) to commercialize the Road Surface Analyzer (ROSAN).
The purpose of this particular CRADA is to provide the highway industry with a product that can characterize pavement surfaces in a safe, efficient, and cost-effective manner. Through the CRADA, FHWA and SES will not only demonstrate that laser technology can successfully measure the quality of paved surfaces but will also provide construction contractors with a valuable tool with which to improve the quality of our Nation's highways.
ROSAN is a laser-based system that was originally developed to record texture characteristics of pavement surface at normal highway speeds along a linear path. With the integration of appropriate pattern recognition algorithms, SES will soon enhance ROSAN's capabilities to measure other surface characteristics such as cracks, joints, grooves, and faulting. ROSAN will also process data in a comprehensible format that can later be incorporated into Pavement Management Systems (PMS) for further analysis. The lightweight, portable ROSAN system will be able to record at least 2 hours of continuous information (approximately 160 km,) before the data buffer has to be downloaded for analysis, and its user-friendly software interface will be easily operated in a point-and-click fashion.
ROSAN results are fast, accurate, and easy to obtain, thus promoting safety while eliminating subjectivity in data, lane closures, and costly traffic control. Automated systems like ROSAN could reduce highway maintenance costs, such as engineering consulting and surveying related support, which amounted to $2.6 billion in 1995. ROSAN's applications can go beyond the highway industry as it d be used to characterize surfaces in airport runways and auto race tracks. For more information or technical notes please contact the following. -
-- Dennis Sixbey , (202) 493-3078.
Load Transfer Restoration - Savings and Service
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| These dowel bars are ready for installation in jointed concrete pavement for load transfer restoration. |
Research has shown that effective load transfer minimizes joint and pavement distresses such as pumping, faulting, and transverse and corner cracking. Load transfer may be measured in terms of the differential deflection of adjacent slabs when subject to a moving load.
Before the mid-1970's, some pavements, and traffic load increases. Several devices have been evaluated to restore the load transfer capacity across joints and transverse cracks of jointed concrete pavements. Of the devices tested, smooth round steel dowels proved to provide the desired load transfer with a cost-effective design. The device consists of a 32- to 38-mm diameter steel bar, 460 mm long, epoxy coated and completely covered with a bond-breaking material. The dowels should be installed ap- proximately mid-depth of the concrete slab and mounted on plastic chairs. Plastic end caps with a 6-mm gap should be installed at each end of the dowels to provide room for thermal expansion of the concrete. Foam core board is used as a weak plane to re-establish the joint at the slot location.
Publication FHWA-SA-97-103 entitled Guide for Load Transfer Restoration will be available next year. The publication will provide guidance on project selection, design, materials, construction and performance information for this technique. -
-- Angel L. Correa , (202) 366-0224.
