Photo Credit: Wael Alqattan

 

• The PCI Big Beam Contest requirs a design and a test of a simply supported beam with a span of 16 feet and maximum total length of 18 feet.

• The beam shall be designed for dead load plus two applied service (UNFACTORED) live loads of 11 kips (i.e in equations 9-1 through 9-7in ACI 318-08 LL = 11 kips each). This translates to factored live loadsof 17.6 k at each loading point.

• The beam must not crack under service live load of 11 kips at each point (22 kips total service live load).

• The beam shall be loaded by applying two point loads, symmetrically,6.5 feet from the center of each support (= 1.5 ft on either side of midspan)as shown.

• The loading mechanism must apply the loads equallyat both points. Use of a single jack and a spreader beam to create two loads is permitted.

 

This diagram shows the load will be applied to the beam and how it will be distributed
Done by: Chad Dietrich

 

The Hulk device that will be used to test the beam at NAU
Photo Credit: Wael Alqattan

 

Judging Criteria **

• The Big Beam Competition will consist of a zone competition and a nationalcompetition. Each entry will judged in relationship to the other entries in the zone. The winner of each zone be entered into the national competition.
  In the national competition, the zone winners will be re-judged against each other to determine the national champion. International entries will be considered as a zone.

• The judging categories shall be

  1. Design accuracy; The beam must to carry at least a total factored live load of 35.2 kips and must not have a total peak applied load of more than 42 kips. The beam shall not crack under the total applied service load of 22 kips.
     Total applied load is defined as the sum of the two applied point loads. Beams meeting these criteria receive 20 points.

     1. Beams which do NOT hold a total applied load of 35.2 kips shall be penalized 2 points for each kip, or part of a kip, below 35.2.

     2. Beams which hold a total applied load of more than 42 kips shall be penalized 1 point for each kip, or part of a kip, above 42.

     3. Beams which crack before a total applied load of 22 kips receive a 5 point penalty. The load/midspan deflection graph must show a peak load either by postpeak softening or by collapse of the beam.
        Stopping the test to avoid the overstrength penalty will result in a score of 0 for this category.

  2. Lowest cost.

  3. Lowest weight.

  4. Largest measured deflection at maximum total applied load.

  5. Most accurate prediction of maximum total applied load, total applied cracking load and midspan deflection at maximum total applied load. Total applied load is the sum of the two applied point loads.

  6. Report quality. Reports MUST contain a discussion of the concrete mix design and the beam structural design.

  7. Practicality, innovation and conformance with code.

 

** For more information about the contest, Please visit: https://www.pci.org/Education/_Related_Content/Related_Content_Files/2014_Big_Beam_Rules_(2694)/