FRP Competition Questions

FRP Competition Questions

Q: After casting our structure, we realized that it was a little bit longer than permitted by the rules and a little bit heavier. Are we allowed to saw cut our specimen to make it conform to the rules?

A: Yes, the specimen may be saw-cut after casting if necessary to achieve dimensions and weight that conform to the rules.

Q: How do we distinguish between the different reinforcement manufacturers' bars, and what are the material properties of each?

A: Please see the "Reinforcement Identification Guide and Product Datasheets" link posted on the competition website.

Q: Can a student team submit an entry in both the Type 1 and Type 2 structure categories?

A: No. Each student team may only submit an entry in one category. If there are two student teams from a university, each team must participate in a different structure type category.

Q: Could you clarify the amount of material that will be sent to the recipients for the competition?

A: Student teams should expect to receive a single reinforcement kit with five sets of three No. 3 (3/8 in. [9 mm] diameter) bars or the equivalent from each of five fiber-reinforced polymer (FRP) manufacturers. Each kit thus contains 15 total pieces of reinforcement.

Q: If I do not have enough materials from the original kit, will I have the opportunity to get more materials to complete the final specimen for competition?

A: No. Each student team will only be sent one complete set of materials.

Q: I see that an electronic copy of the Official Mix and Cost Form is due March 1 and that a hard copy is due March 26. Do the two have to exactly match in terms of predicted loads?

A: The predictions must match exactly. Student teams are not permitted to adjust their predictions after the March 1 deadline. Should they do so, the prediction values submitted on March 1 will be used for determining the prediction discrepancy.

Q: The three cylinders and the slump test that are listed on the Official Mix and Cost Form aren't mentioned in the official rules or any other page of the submittals. Is it a requirement to perform these tests?

A: All requested information on the Official Mix and Cost Form must be provided, so you will need to perform a slump test and break three cylinders for 7-day strength. A fourth cylinder must also be produced and brought to the competition along with the structure.

Q: Is our batch weight used for cost determination based on how much material we used to produce our specimen or is it based on our mixture design for (1 cubic yard or 1 cubic meter)?

A: Neither. Costs are determined based on the entire batch weight of the concrete volume used for casting the structure. More specifically, this includes the concrete for the structure, the slump test, four cylinders, and any "extra" concrete that is left over after placing. You must pay for all concrete that you batch with your competition beam. For example, if you typically batch for 30% losses, you will need to pay for that concrete.

Q: We only have 4 x 8 in. (100 x 200 mm) and 6 x 12 in. (150 x 300 mm) cylinders in our lab. May we use one of these sizes for the competition or is it mandatory to use 3 x 6 in. (75 x 150 mm) cylinders?

A: For the cylinder that is brought to the competition, student teams may substitute a 4 x 8 in. (100 x 200 mm) cylinder for the 3 x 6 in. (75 x 150 mm) cylinder size specified in the rules. For the three cylinders used for evaluation of 7-day compressive strength, any larger size cylinder may be used provided that the cylinder has a height:diameter ratio of 2:1.

Q: Can we use capping for the concrete cylinders?

A: You may cap the cylinders you test for 7-day strength, but the cylinder that is brought to the competition should not be capped.

Q: Can we reuse the concrete for the slump test in one of our cylinders? This would save on cost.

A: Yes, reusing the slump test concrete in the cylinders or structure is permitted, should teams choose to do so.

Q: On the diagram, it says that the end reactions are applied through flat plates that are at least 2 x 2 in. (50 x 50 mm). The design that we are working with won't work with plates that size. The wording makes it seem like bigger plates are a possibility.

A: The beams must be able to be tested with plates any size from 2 x 2 in. (50 x 50 mm) on up. Designs that do not meet this requirement may not be able to be tested at the competition. It is the team's responsibility to ensure that their beam can be safely tested with end reactions applied through flat plates that may be as small as 2 x 2 in. (50 x 50 mm).

Q: Of what material will the reaction points be composed of when the structure is tested?

A: Steel.

Q: What is the length of one piece of GFRP reinforcing bar given for competition?

A: All reinforcement is 39 in. (990 mm) in length.

Q: May we use a mixture of reinforcing bars?

A: Different types of FRP bars may be used in the same structure, as long as the only reinforcing materials used are from the FRP reinforcing materials kits and all materials used are reported on the Official Mix and Cost form.

Q: Is the FRP allowed to show?

A: FRP may be exposed in the structure.

Q: What cannot be done to the reinforcement bars, or what are the limitations on the manipulation of the bars?

A: The only limitation on manipulation of the bars or grids per the rules is that you are not permitted to prestress the reinforcement.

Q: Can the FRP surface be roughened to increase or decrease the bond strength?

A: Yes, the rules permit this. However, the surface of the bars may not be coated with any material. The bar surface (original or modified by roughening) must be in direct concrete with the concrete within which it is embedded.

Q: Are you able to bend the FRP bars in any way to create a hook at the end of the bar? Can the bars be melted?

A: You should research the materials prior to doing anything to the bars and grids other than cutting them, as it is possible that activities such as heating may destroy material properties. Also keep in mind the stress-strain characteristics of these materials that are linear elastic to failure—or in other words, the bars will not yield.

Q: What constitutes "mechanical anchorage" of FRP bars?

A: "Mechanical anchorage" is the use of any type of mechanical device (such as end plate) to anchor the bar, other than relying on the bond between the concrete and reinforcement.

Q: Are we permitted to use metal wires or similar items such as paper clips to locate the FRP inside the beam?

A: Yes, but only if the metal is galvanized (zinc-coated) or coated with nonmetallic materials. Otherwise, bar supports must be nonmetallic. Regardless, any bar supports must be located outside the clear span and must not act to enhance the behavior of the structure, such as by anchoring the bar in the concrete.

Q: Do glass fibers qualify as aggregate?

A: No, glass fibers do not qualify as aggregate. Fiber-reinforced concrete (a concrete mixture with short fibers, no matter what the type) is not permitted.

Q: Is Micron 3 allowed?

A: Only materials listed on the Official Mix and Cost worksheet are allowed. Although Micron 3 may meet requirements of ASTM C618, it is not fly ash meeting ASTM C618 so it would not be allowed.

Q: Is the use of lightweight core permitted for the structure?

A: It depends on what you consider a "lightweight core" to be. If you mean a core of lightweight concrete, then yes, that is permitted. But if the lightweight core is made of any material other than concrete, it would not be permitted.

Q: As far as type of cross section, we read the rules for competition several times and we did not find anything saying that we are not allowed to do a hollow section, so just to make sure, are we allowed to have a hollow section for our beam? And if yes, are we able to use something like a pipe to create the hollow or is there any restriction on what we use to make the hollow happen in our beam?

A: A hollow section is permitted by the rules; however, nothing used to create the void may permanently be left attached to the member. The final structure must be comprised of concrete and FRP reinforcement.

Q: Are the only cementitious additives that can be added to the mix the ones listed in the Mix and Cost Worksheet?

A: Yes. Only cement and supplementary cementitious materials that meet the ASTM designations on the mix and cost sheet are permitted. These include ASTM C150, ASTM C595, ASTM C1157, ASTM C618, ASTM C989, and ASTM C1240.

Q: Section 2.5.7 states that the structure must be fabricated with at least one (1) full piece of the FRP reinforcing material. Does that mean 1 whole piece (as a whole), or can that 1 piece be cut in any way I like?

A: At least one of the reinforcing bars provided in the kit must be used, but that specific bar may be cut into as many segments as desired. Additionally, however, each structure must use a minimum amount (total length) of FRP reinforcement corresponding to the length of a single original bar. Note that the number of bars entered on the Mix and Cost Worksheet should be the number of original lengths of bar from which any smaller segments were obtained.

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