Carbon Fiber Reinforced Polymer (CFRP)
REBAR

The Aslan 200 series provides designers the greater modulus and tensile strengths of carbon fiber in a non-metallic reinforcing bar. Aslan 200 can be used for both new construction and as a strengthening material for the novel technique known as "Near Surface Mount" or NSM strengthening. With a proprietary end anchorage, the Aslan 200 bar can be used in un-bonded post tension or pre-stressing applications. The Aslan 200 series features a textured surface whereas the Aslan 201 series is a sand coated surface. Both versions have the same physical properties.

Features of Aslan 200 CFRP Rebar

The Aslan 200 series of Carbon FRP bars are significantly more expensive than the Aslan 100 GFRP Rebar, but a greater tensile modulus and greater creep rupture threshold offer a number of unique advantages.
For strengthening of existing structural elements, Aslan 200 may be used to increase the flexural or shear capacity of a member. In this technique, the Aslan 200 is placed in a groove cut into the surface of the element. The rod is embedded in a cementitious grout or high strength structural epoxy adhesive. NSM strengthening is appropriate for concrete, masonry or wood structural elements.
Aslan 200 bars can also be used for pre-stressing or post-tensioning utilizing Hughes Brothers proprietary anchorages.
Unlike Aslan 100 GFRP, Aslan 200 CFRP bars are semi-conductive of thermal, electrical and radio-frequency energy.

Transverse Direction ...... 41 to 58 X 10-6/F (74 to 104 X 10-6/C)
Longitudinal Direction ...... -4 to 0.0 X 10-6/F (-9 to 0.0 X 10-6/C)

Research has shown that the bond strength does not vary significantly with varying concrete strength, provided the concrete block is properly sized to prevent splitting.

In order to control the embedment length within the block, the rods are prepared with a bond breaker, which consists of soft plastic tubing placed around the rods to prevent contact between the rod and the concrete. The embedment length is 5 bar diameters.

Stirrups, Shapes and Bends

Bent shapes with FRP bars are readily available in the Aslan 100 GFRP family, but at this time are not available for the Aslan 200 series CFRP bars.

Please see the Aslan 100 literature for information about GFRP stirrups and bent shapes.

Design Considerations - New Construction

Direct substitution between CFRP, GFRP or steel bars is not possible due to various differences in the physical and mechanical properties of the materials.

ACI440.1R-06 "Guide for the Design and Construction of Concrete Reinforced with FRP Bars" provides the design engineer with the latest information necessary to perform a conservative and safe implementation of the Aslan FRP family of reinforcing.

Handling and Placement of CFRP Bars for New Construction

When necessary, cutting of the CFRP rebars should be done with a masonry or diamond blade, grinder or fine blade saw. A dust mask is suggested when cutting the bars. It is recommended that work gloves be worn when handling and placing CFRP rebars.

CFRP rebar has a low specific gravity and may "float" in concrete during vibration. Care should be exercised to adequately secure CFRP bars in formwork using chairs, plastic coated wire ties or nylon zip ties.

Care should be taken to avoid abrading the CFRP bars by dragging them or rubbing against other surfaces. This may degrade the tensile strength of the bar.

Provisons in ACI 440.5-08 "Specification for Construction with Fiber-Reinforced Polymer Reinforcing Bars" describe implementation issues for FRP bars in detailed mandatory language.

Design Considerations - NSM Strengthening

Structural strengthening using Aslan 200 is based on the principles of ACI440.2R-08 "Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures"

A companion product to Aslan 200 is the Aslan 500 CFRP Tape.

Aslan 500 is intended for flat surfaces and is embedded in a saw kerf cut. See the Aslan 500 literature for more details.

Installation of Aslan 200 for NSM Strengthening

After assessment of the condition of the existing structure and design by a competent professional, installation of the CFRP Tape is performed according to the following general outline. (photos courtesy of Univ of Missouri Rolla)

1. Using a diamond blade concrete saw or grinder, a groove of 1.5 times the bar diameter is cut.
2. The groove is thoroughly cleaned using a vacuum and/or compressed air.
3. The inside of the groove is sandblasted or lighted abraded with a wire brush.
4. The slot is masked to prevent excess adhesive from marring surface.
5. Groove is half filled with Structural adhesive. Care should be made to avoid entrapped air voids.
6. The CFRP Bar is seated in the groove.
7. Remainder of the groove is filled with adhesive.
8. General clean up and removal of any masking.

• Master Builders Concresive 1420 & Concresive LPL
• Hilti RE 500
• DeNeef Enforce CFL Gel
• Unitex Propoxy 400
• Pilgrim Magmaflow CF