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Concrete Pavement Technology Update

January 2006

MIT Scan-2 dowel bar placement evaluator
DOC-500 impact-echo device
air void analyzer
Above, some of the devices available through the CPTP loan and onsite demo program: MIT Scan-2 dowel bar placement evaluator (demonstrated at the January 2006 Transportation Research Board meeting); DOC-500 impact-echo device; air void analyzer.

CPTP Equipment Loan Program

To promote the implementation of new technologies, CPTP is providing onsite demonstrations and month-long loans of equipment tested under the program. States will be able to borrow the following devices:

  • MIT Scan-2—a nondestructive testing (NDT) device for evaluating dowel or tie bar placement (three devices available). CPTP evaluations showed the MIT Scan-2 to be reliable, efficient, and accurate within reasonable limits for both basket and insertion bar installation methods. The device can be used on fresh concrete and can measure up to 200 joints in an 8-hour shift. FHWA's Sam Tyson characterized the technology as one that can be used at the start of a paving operation to identify and correct dowel misalignment that otherwise could lead to locked joints and early distress.
  • Maturity testing system—to estimate in situ concrete strength (three systems will be available). The systems predict concrete strength development with time, provide continuous feedback on curing conditions, and can be used to determine appropriate times for joint sawing or opening a pavement to traffic.
  • NDT impact-echo device—used to determine concrete slab thickness and to detect the integrity of concrete (two German Instruments DOC-500 units available). The system uses impact-generated waves that propagate through portland cement concrete and are reflected by abrupt changes in internal characteristics (voids, etc.) and external surfaces. Sensing those changes or surfaces enables the equipment to estimate slab thickness and assess integrity.
  • Air void analyzer—a device for testing fresh concrete to evaluate the air void system (one available).

Conditions for Loans

  • Onsite demonstrations and equipment loans are provided on a first-come, first-served basis.
  • Limited onsite training and technical support, if needed, are provided with each loan.
  • The basic loan period is 1 month, excluding the time for shipping and training.

The primary purpose of equipment loans is to provide agencies opportunities to evaluate the devices. However, since an important aspect of evaluation is to determine if the devices are practical in actual construction applications, the States may use the devices in limited production work. There are no restrictions on the use of the data collected using the borrowed equipment.

Agency Responsibilities

To help the loan program run smoothly and to further evaluate the capabilities of the equipment, requesting agencies are charged with the following responsibilities:

  • Safekeeping of the device while it is in the agency's possession.
  • Return shipment of the device to the location designated by FHWA.
  • A brief report documenting the agency's experience, to include the following:
    • A description of the evaluation conducted, including photos, if possible.
    • The agency's assessment of the device—whether it was found useful, practical, or not suitable. Include suggestions for improvement, if any.
    • The agency's potential future plans—how the agency may use the device (e.g., as part of a specification requirement, quality control/quality assurance program, or research study).

To Arrange a Loan or Demo

Access the CPTP Equipment Loan Request Form.

E-mail or fax the completed form to Sam Tyson, FWHA (sam.tyson@fhwa.dot.gov; fax 202-493-2070), or to Shiraz Tayabji, CTL Group (STayabji@CTLGroup.com; fax 410-997-8480).


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Updated: 04/07/2011
 

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United States Department of Transportation - Federal Highway Administration