The following general requirements and recommendations are provided for using V-ROD fiberglass rebars in the construction of reinforced concrete structures.
HANDLING AND STORAGE
V-ROD reinforcing bars, while inherently very durable, are made with a matrix of synthetic resin rendering them liable to surface damage if abused. Deep scoring by sharp objects will reduce their durability and performance capacity; therefore care is advised in the handling of these materials during storage and placement. When conditions on the job site permit, bars should be delivered to a storage area. FRP bars are more tolerant of handling, storage, and placement variations than epoxy-coated bars, but need to be more carefully handled than uncoated steel reinforcing bars.
The following specific storage and handling guidelines will minimize any damage to the bars or the bar handlers:
- Bars should be handled with heavy duty working gloves to avoid hand cuts and injuries from sharp edges.
- When storing bars outdoors, placing them directly on the ground should be avoided; timber pallets should be placed under the bars to keep the bars free from mud and to provide easy access.
- V-ROD is inherently highly corrosion resistant, but ultraviolet rays and chemical substances can induce undesirable surface blemish if stored in such conditions for extended periods of time. If stored outdoors, the bars should be covered with opaque plastic or other types of cover to protect the bars from the external environment. Protection from moisture exposure is not needed.
- Dirt, oil or grease that is present on the bars in significant quantities should be removed before placing concrete by using high-pressure water and/or wiping or spraying the bars with suitable solvents.
- V-ROD reinforcing bars are light and flexible in comparison to steel rebar. Hoisting bundles of bars should be done carefully until all involved personnel are familiar with the way the bar reacts to handling. It is desirable to use a spreader bar to facilitate handling and prevent excessive bending.
- V-ROD bars can be quickly and easily cut with a high speed grinding cutter, diamond-bladed chop saw, or a hacksaw. Bars should never be sheared.
PLACEMENT AND ASSEMBLY
Placing of V-ROD reinforcing bars is done in a similar fashion to steel bars. Unless otherwise specified in project specifications, the bars should be placed within the tolerances specified in ACI 117 (“Standard Tolerances for Concrete Construction and Materials”). Common placing practices should apply with the following exceptions:
- Because it is lightweight, fiberglass reinforcement should be adequately secured in the forms to prevent displacement by concrete placement or workers. Plastic or non-corrosive chairs can be used to elevate the rebar on spacing determined by the bar diameter.
- Plastic or nylon ties, and plastic snap ties can be used in tying the bars in applications where corrosion resistance or total absence of metals is paramount. Standard metal tie wire, coated tie wire, and stainless steel tie wire can also be used. Fiberglass rebar can also be lap spliced to metal rebar; mechanical fastening devices should not be used.
- Whenever continuity is required in the reinforcement, lapped splices should be used. Mechanically connected or welded splices are not possible with composite reinforcing bars. The length of lap splices varies with concrete strength, type of concrete, rebar grade, size, spacing and cover. In the absence of other specifications, an overlap of forty (40) bar diameters should be utilized.
V-ROD is a thermoset composite, and cannot be bent after it has been polymerized (cured). Since it is shipped in a fully cured form, it cannot be bent on job site. Bends can be produced during the manufacturing process in most shapes that can be obtained with steel rebar, although typically a little more generous bend diameter will be required. As a general guideline, multiplying the bar diameter (in inches) by a factor of 4 will give you an approximate minimum bend radius for a 90-degree bend. Similarly, multiplying the bar diameter by a factor of 8 will give you the minimum bend diameter for a 180-degree bend. In any job where bending dimensions are critical, bending capability should be verified prior to placing an order. Based on testing, approximately 50% of the guaranteed design strength of a straight bar is retained after making a bend.
V-ROD meets ISO 9001:2000 standards. Through routine sampling and inspection, quality control tests are carried out during production to ensure that products meet all specifications and are within exacting dimensional tolerances. Certification to these results is available by prior request. Test reports are also available from third-party independent testing agencies and universities regarding specific product performance in the following areas:
- Mechanical properties, including tensile strength, tensile modulus of elasticity, fatigue strength, and ultimate strain
- Bond strength
- Durability in alkaline environments