Reclamation hosts 2018 PCI Big Beam Load Test

Written by: Emily Quinn

Students pose in front of their beam prior to testing
Students pose in front of their beam prior to testing
On March 27, senior engineering students from Colorado State University participated in the 15th annual Prestressed Concrete Institute’s Big Beam Load Test Competition. CSU is participating for the third time. The PCI Big Beam Competition provides students with an opportunity to design, fabricate and test a precast/prestressed concrete beam with the help of a local precast concrete producer.

The PCI Big Beam Load Test Competition was the first event of its kind held in Reclamation’s Technical Service Center. Janet White, Group Manager for the TSC’s Concrete, Geotechnical and Structural Laboratory, coordinated the event and hopes to continue providing support for the competition in the future.

Plum Creek Structures was the local PCI producer sponsoring the beam test. The beam was tested at Reclamation’s Technical Service Center using the Five Million Pound Universal Testing Machine. Due to the size of the beam, Reclamation’s TSC was the only facility available to accurately test the load and monitor deflection of the beam.

Student-constructed concrete beam
Student-constructed concrete beam

The students’ entry was judged based on several criteria, including design accuracy, lowest cost, lowest weight, and largest measured deflection at maximum total applied load. Additionally, the beam was judged based on the students’ most accurate prediction of carrying capacity, total applied load at first flexural cracking, and midspan deflection at maximum total applied load.

The beam could not crack before 20,000 pounds, and was required to be 20 feet long. The beam was required to break before reaching 39,000 pounds, otherwise penalty points would be added. The students predicted that their beam would crack at 30,000 pounds, and would fail at 34,200 pounds with a deflection rate of 4.4 inches.

The full size, prestressed concrete beam was loaded to service, ultimate, and failure under the Bureau of Reclamation’s Five Million Pound Universal Testing Machine, located in the Technical Service Center on the Denver Federal Center.

Fred Travers and Westin Joy, with the Concrete, Geotechnical, and Structural Laboratory Group, loaded at a rate of 2,000 pounds per minute, and continued to do so until the beam failed. Ultimately, the students’ beam cracked at about 26,000 pounds, and failed at around 41,000 pounds. The beam’s deflection was measured out to be 3.36 inches.

The participants were also required to produce a high-quality report that contains a discussion of the concrete mixture proportions, and the beam’s structural design. Practicality, innovation and conformance with code requirements were also included in the judging criteria.

The student team consisted of five seniors from CSU, including Aatir Farooq, Abdullah Algasem, Claudia Quezada, Jordan Illian and McKenzie Flaherty. The team was advised by faculty member Dr. Rebecca Atadero with the help of Greg Black. There are six PCI zones in the competition which wraps up in August, at which time the winning teams will be determined.

Published on April 04, 2018