FRP Competition Questions

FRP Competition Questions

Q: Can I put my beam GRFT bar with 92 cm and another one with 50 cm?

A: Yes.

Q: Does our beam need to conform to ACI 440 in any way?

A: The beam MUST conform to FRP Composites Competition Rules. It may or may not conform to ACI 440.

Q: Can FRP bars be used as aggregate?

A: Section 2.5, Structure Materials of the Competition Rules, states that only materials listed in the Official Mix and Cost worksheet may be used. This would include the reinforcement. The bars may be cut up and added to the beam, but they would be considered "reinforcement" and not part of the concrete mixture design as aggregate. They should, therefore, be shown scattered in the sketches of the Official Mix and Cost worksheet.

Q: Is the T-beam a rectangular shape?

A: The T-beam shape is not a rectangular shape itself. It is comprised of rectangles, but not a single rectangle. Therefore, the team would enter "no" in the Official Mix and Cost worksheet where it asks, "Is this shape rectangular?"

Q: How can we attach/support shear reinforcement within the clear span? May we use ties or other methods?

A: Section 2.6.3 of the Competition Rules states that "Reinforcing supports are not permitted in the 850 mm clear span. Any manner of bar support including chairs, wires, and precast concrete blocks may be used outside the clear span, as long as the bar support does not act to enhance the behavior of the structure." This section does not refer to ties used to connect bars to each other or to connect bars to the reinforcing supports (chairs, etc.). Ties may be used within the 850 mm clear span. Ties must be nonmetallic or must be galvanized.

Q: Does anyone reach 67 kN before reaching 3.5 mm deflection?

A: This is possible if a team designs a beam that leads to this behavior. Section 3.4 of the Competition Rules addresses this, and states that "If a structure fails to reach a deflection of 3.5 mm (0.14 in.) prior to failing or reaching the test fixture’s capacity of 67 kN (15,000 lb), (P3.5) will be taken as the maximum load achieved (as specified in Paragraph 3.3) less the seating load of 0.25 kN (56 lb)."

Q: Can we use an I-section shape?

A: Yes, an I-section shape is permitted. Note that it would be classified as a non-rectangular shape. Therefore, the team would enter "no" in the Official Mix and Cost worksheet where it asks, "Is this shape rectangular?"

Q: What is the design compression strength for GFRP?

A: This information is not provided as part of the competition. Student teams are encouraged to do research on this by seeking out information in ACI literature and scholarly journals.

Q: Can we put shear bars inside the beam?

A: Yes. However, it should be noted that the shear bars may not be directly supported themselves with chairs, wires, precast concrete blocks, etc. Section 2.6.3 of the Competition Rules states that "Reinforcing supports are not permitted in the 850 mm clear span. Any manner of bar support including chairs, wires, and precast concrete blocks may be used outside the clear span, as long as the bar support does not act to enhance the behavior of the structure." This section does not refer to ties used to connect bars to each other or to connect bars to the reinforcing supports (chairs, etc.). Ties may be used within the 850 mm clear span. Ties must be nonmetallic or must be galvanized.

Q: Can we use any shape for the section? Can we have any section whether I-beam or T-section, whether inverted or not?

A: Yes, any shape may be used as long as the size requirements of Section 2.2 of the Competition Rules are met.

Q: Does a "prismatic section" mean that the FRP must also be constant along the section?

A: No. For this competition, a section is defined as prismatic (or non-prismatic) based only on its overall concrete section shape. Changes in reinforcement location or quantity along the length of the beam are not considered in establishing whether a shape is prismatic or not prismatic.

Q: How long must an FRP bar be inside the concrete beam? What is the minimum length for FRP bars inside the beam?

A: There are no limitations on the length of the FRP bar used in the beam, except that "The structure's overall length may not be less than 950 mm (37.4 in.) nor more than 1000 mm (39.4 in.), including any protruding reinforcement."(Section 2.2 of the Competition Rules.)

Q: Does a minimum size exist for 200 mm wide by 200 deep (specified in the rules as maximum sizes)? We were thinking of doing a formwork 100 mm wide by 100 mm deep.

A: 200 cm is the maximum width and maximum depth. There is no minimum dimension required for the structure, except for the minimum length of 950 mm. There are no minimum cross-sectional dimensions. However, as indicated in Section 2.2, the structure must be able to be placed on supports and loaded as shown in the Structure Geometry Requirements Diagram. The structure must also meet the minimum weight requirement of 5 kg.

Q: If we place three FRP bars for compression and two bars for tension with 92 cm length inside a 95 cm length beam, will this make the cross section prismatic?

A: This would be a prismatic section if the concrete cross section remains prismatic. For this competition, a section is defined as prismatic (or non-prismatic) based only on its overall concrete section shape. Changes in reinforcement location or quantity along the length of the beam are not considered in establishing whether a shape is prismatic or not prismatic.

Q: Are we allowed to cast trial beams; and, if so, does that material count toward our batch size?

A: Yes, the team may cast trial beams. Section 2.5.5 of the Competition Rules states that "Teams must provide the measured weights of all materials used in the concrete batch prepared to cast their competition structure…" Therefore, the weight of materials used to cast trial beams or to experiment with mix designs should not be included in your Official Mix and Cost worksheet.

Q: Can I put foam inside concrete beam mix? Can we use foaming concrete as a lightweight concrete?

A: Only materials listed on the Official Mix and Cost worksheet are allowed. Neither foam (such as Styrofoam), nor reactive foaming agents that produce cellular concrete, may be used.

Q: Section 2.5.3 of the rules say that any type of nonmetallic aggregate may be used. Is silica sand permitted? What would be the unit price on the cost form of the material?

A: Silica sand, which is an ultra-fine aggregate used in ultra high performance concrete (UHPC), is permitted and should be considered as “Fine Aggregate” on the Mix & Cost Form. Be sure to note that silica sand is different that silica fume, and silica fume would not be considered as aggregate.

Q: The rules say that no supports like wire or chair are allowed in the middle clear span of 850 mm. But right now we are thinking about casting the beam with the FRP reinforcement hung from top with tape (electric tape or clear tape) or threads. Are the tapes or threads allowed to stay in the middle 850mm clear span, since they are not solid supports and will not have any structural contribution?

A: No. Per Section 3.6.3 of the rules, all reinforcing supports – regardless of the type of support used – must be located outside of the middle clear span of 850 mm.

Q: According to the rules Section 1.2, each team must consist of not more than eight students currently enrolled in an undergraduate program at any college or university worldwide. But in the Official Mix & Cost Form there is only space to put the name of five team members. So how many team members are allowed to register?

A: This is simply a mistake on the Mix & Cost form. Eight team members are permitted to register, and this information is collected during the team registration process. It is not important that the team members’ names actually appear on the Mix & Cost form itself, so this information may be left blank or up to five names may be listed.

Q: Is it possible for one university to participate in two different categories with two different teams?

A: No. Each student team may only submit an entry in one category. Only 1 team is permitted per school/university. If an entry is submitted into the incorrect category, the competition committee will switch the entry to the correct category.

Q: Can we have a section that is less than 20 cm ×20 cm?

A: Yes. 20 cm is the maximum width and maximum depth. There is no minimum dimension required for the structure, except for the minimum length of 950 mm. There are no minimum cross-sectional dimensions. However, as indicated in Section 2.2, the structure must be able to be placed on supports and loaded as shown in the Structure Geometry Requirements Diagram. The structure must also meet the minimum weight requirement of 5 kg.

Q: Do glass fibers, metallic fibers, or polypropylene fibers qualify as aggregate?

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

Q: On the ACI website, past winners and scoresheets are available. Would it be possible to view their submitted design .pdfs as well?

A: PDFs from previous competitions are not shared. However, the past scoresheets provide insight into how scoring is done.

Q: Are integral pigments and color-coating treatments not allowed in the competition? Are there any methods of personalizing the structure outside of the identification number or is this a deliberate competition design consideration?

A: Technically, Section 2.5.1 of the rules would prohibit this. However, in the spirit of the competition, we would permit personalization of the structure provided that it does not impact the structural behavior in any way. Stickers, decorative writing on the side of the beam, minor nonstructural attachments (for example gluing small plastic letters to the side of the beam), etc., would be acceptable. However, nothing that is required to be integrated as part of the concrete mixture itself (i.e. pigments) should be used.

Q: There's nothing noted in the rules about longitudinal reinforcement. I assume very thin ( 2.5 to 5 mm in diameter) metal rods are not allowed in the beam?

A: Please see Section 2.5 of the rules, including the following:
2.5.1. Use only materials listed in the Official Mix and Cost worksheet.
Metal rods of any kind are not allowed in the beam. Please also note that bar supports must conform to Section 2.6.3, which restricts the use of metallic materials.
2.6.3. Reinforcing supports are not permitted in the 850 mm clear span. Any manner of bar support including chairs, wires, and precast concrete blocks may be used outside the clear span, as long as the bar support does not act to enhance the behavior of the structure, such as by anchoring the bar in the concrete; these bar supports are NOT included in the total cost. All reinforcement supports must be made from nonmetallic materials or must be galvanized (zinc-coated) or coated with nonmetallic materials. Mechanical anchorages, if used, must be made from the materials provided, as specified in paragraph 2.5.7 and ARE included in the total cost.

Q: Does the structure weight in section 2.4 of the rules refer to the beam weight including the FRP reinforcement?

A: The total structure weight is the beam weight and DOES include the weight of any FRP reinforcement that is used.

Q: Is there a cost for the kit to be shipped?

A:  No cost is required of the teams. Only 1 kit is provided per team.

Q: How quickly can we receive our kit?

A: Kits will be shipped once both required documents are uploaded to your registration file (the FRP Kit Order Form and the Verification Letter.) Expect the kit within 10 business days.

Q: The rules indicate the FRP kit will be sent with the manufacturers' data sheets, but it was not included in the package.

A. We apologize for this miscommunication. Please find the data sheets on the right side of the FRP page.

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. Only 1 team is permitted per school/university. If an entry is submitted into the incorrect category, the competition committee will switch the entry to the correct 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 by the pre-competition deadline date and that a hard copy is due at check-in. 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 pre-competition deadline date. Should they do so, the prediction values initially submitted 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.

Q: Questions regarding the beam rehearsal: Will they use any standard in the testing machine? Will the test be standardized by any test standard?

A: The test procedure is defined in Section 3. The Testing Process of the FRP Composite Competition Rules. General information taken from this section states that the load will be applied by a pivoting load plate at an approximate rate of 2.5 mm/min. A seating load of approximately 56 lbs will be applied and the seating load and piston movement will be recorded. Additional load will be applied until the structure fails or is loaded to the test fixture's capacity of 67 kN (15,000 lbs).

Q: Can we have 2 mix designs for different areas of our beam

A: Yes, you may have two different mix designs. However, the team must designate which mix design is being used in what areas of their structure on their structure drawings. The team should submit two different official mix and cost forms with appropriate volumes for each mix design shown. Types and quantities of FRP bars should be shown on only one Official Mix and Cost From.

Q: How do the judges base the percentages of silica fume and slag in our concrete mix?

A: Percentages of silica fume and slag are defined in Section 4 Structure Cost. Specifically, Sections 4.4.7, 4.4.8, and 4.4.9 address the percentages of slag and Sections 4.4.10 and 4.4.11 address the percentages of silica fume that are evaluated for sustainability credit. The percentages are calculated as the measured batch weight of silica fume (or slag) related to the sum of the measured batch weights of all cementitious materials (including cement, fly ash, slag, and silica fume).

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