EPD Competition Questions

Q. Reinforcement in the device: Should the device include reinforcement (be made of reinforced concrete), or is the only permissible reinforcement the fibers described in the ASTM standards outlined in the competition rules?

A. See 3.3, with attention to 3.3.4. Fibers conforming to ASTM C1116 Section 4 are the only permissible reinforcement.

Q. Metallic aggregates: In section 3.1.1.3, when it states that "metallic aggregates are not permitted," does this refer specifically to metallic fibers or to steel bars?

A. This refers to metallic aggregates (e.g., steel shot). Steel bars are not permitted. Metallic fibers are permitted per 3.3.

Q. Composition of test cubes: Should the cubes only contain a concrete mixture, without any type of fibers, special aggregates, or other additional elements?

A. See 2.3.2. Cubes shall be cast from the UHPC matrix only, comprising the same ingredients and proportions as the UHPC mixture but without fibers.

Q. Aggregate size: The permitted aggregate size is not entirely clear to us. Could you please clarify this point?

A. There are no restrictions on aggregate size.

Q. Is the use of carbon fibers allowed in the concrete mixture, in accordance with the competition guidelines?

A. Fibers of any kind are allowed as long as they conform to Section 3.3 of the Rules and Section 4 of ASTM C1116.

Q. The fibers I’m planning on using have a specified length of 2 in. (approximately 51 mm); would it be acceptable to use them?

A. Fibers with a nominal size of 2 in. (50.8 mm) will be allowed.

Student Competition Questions

Please contact:

Jaeden Jackson
American Concrete Institute
38800 Country Club Drive
Farmington Hills, MI 48331
Fax: +1.248.848.3701
Email: students@concrete.org