We are looking for technologies or devices that can easily and non-destructively evaluate any deterioration in reinforced concrete structures. This deterioration might include such conditions as rebar corrosion due to salt or chloride damage, cracks, or peeling, floating, separation, or exfoliation of the concrete structure. The ability to assess structures non-destructively will streamline maintenance inspections. The targeted rebars are about 13 to 32 mm in diameter and are located about 50 to 100 mm deep within the concrete.

Background:

Currently we mainly conduct a visual inspection of the appearance of RC structures and evaluate deterioration such as cracking, floating, peeling, or separation. For coated RC structures, we cannot confirm the deterioration of parts that are covered by the coating material.

For parts where salt or chloride damage is expected after visual inspection, we collect a concrete core from the RC structure (this is a destructive inspection), calculate the chloride ion concentration (JIS 1154) of concrete at the position of the reinforcing bar, and indirectly evaluate the corrosion state of the reinforcing bars. When collecting the concrete core, primary issues include:

  • The place where the concrete core is collected may become a weak point for deterioration in the future.
  • It takes time to evaluate the core. On-site work (collecting the concrete core and repair of the core hole) takes two days. The chloride ion concentration measurement takes about ten days.
  • Concrete core sampling can evaluate only the specific point where the core was removed, and cannot adequately evaluate larger areas.
  • Longer-term continuous evaluation at the same place cannot be done.
  • For coated RC structures, the covering material must be cut and removed.

Constraints:

The proposed solution must satisfy at least one of the bulleted evaluation items.

  1. For the coated RC structure, we are seeking inspection technologies and/or devices to evaluate the deterioration (rebar corrosion, cracking, peeling, or separation) using non-destructive methods applicable from outside of any coating material and without removing the coating material. Typical covering materials are:
    • Carbon fiber coating
    • Polyester fiber coating
    • Fiber-reinforced plastics coating
  2. We are looking for non-destructive inspection technologies and/or devices that can easily and quickly detect corrosion of reinforcing bars inside the RC structure. (Minimal time lag, in-the-field reporting.)
    • The proposed solutions need not be limited to “chloride ion concentration measurement test.”
    • We are seeking technologies that can evaluate the amount and speed of corrosion inside the RC structure.
    • We are looking for technologies that can be applicable to larger “areas” (not a specific point) and longer-term continuous evaluation.
    • Since the target structure is in a wet condition, we are hoping for solutions that are applicable in wet condition.
    • We are looking for technologies that can work on coated RC structures without removing the covering material.

Possible solution areas:

We assume that there are solutions in the following technology and business areas:

Nondestructive inspection equipment for deterioration of

  • port facilities
  • road and railway facilities
  • bridge facility degradation

Maintenance and management of civil engineering and building structures.

Desired Timeframe:

Within 12 months

Field Of Use and Intended Application:

Nondestructive inspection of reinforced concrete structures (RC structures)

Desired Outcome:

  • We must clarify the development process of any proposed solutions within FY2017.
  • In the absence of finished products, we can act as a joint development partner.
  • We are looking for solutions that can evaluate deterioration (rebar corrosion, concrete cracking, floating peeling etc.) under any covering material without removing the covering material.
  • We do not limit the type of solution, but would like to evaluate technologies that can determine at least one of the following items:
    • Measurement of chloride ion concentration (at the surface and at the rebar position)
    • Determine the corrosion condition of internal rebars (corrosion amount, corrosion speed)
    • Determine the corrosion condition of coated concrete (rebar corrosion, cracks, floating separation, etc.)

Previously Attempted Solutions:

Test studies are being conducted with rebar corrosion detectors (iCOR Giatec). We are examining the detection accuracy now.

Comments:

In case the proposed solutions are in early stage of technology development, we will consider joint development.

Proposals from inspection service companies with innovative evaluation system / new inspection technologies will also be considered.

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