1. Participation is open to all allied and producer members of TACA, as well as Universities.
   
   
2. Participants will have the option to batch their concrete either in a plant or lab setting. The overall winners will be announced (i.e. 1st, 2nd and 3rd place).
   
   
3. The contest will be based on the lowest ratio of unconfined compressive strength (UCS) for ONE (1) 4in x 8in cylinder broken at 3 days and one at 28 days from the time of cast, plus or minus six hours. Ratio is 28:3. (example 8000 PSI at 28 days 2000 PSI at 3 days = 4.00 Ratio.) Your goal is to achieve the lowest ratio as you can. Minimum of 4000 PSI at 28 days and highest at 3 days. Tie breaker will go to the highest 3 day strength in PSI.
   
   
4. Participants may cast multiple cylinders and multiple batches to obtain or display the best work but only one submission is allowed per student or TACA Member.
   
   
5. After initial set and transport (if needed), cylinders must be cured in a water tank or room with 100% humidity at 73+/- 3°F. (i.e. typical cylinder curing conditions are required).
   
   
6. Cylinders may be broken by any laboratory convenient to the participant. Cylinders may be prepared in any way convenient to the laboratory but no caps (neoprene, sulfur, etc.) may be used. (i.e. grinding, excellent finishing, or sawing are allowed).
   
   
7. Result submissions shall be received no later than 11:59 PM on June 30, 2020 by Lisa Lukefahr at lisa@texasconcrete.org.  The attached Cylinder Verification Form should be signed by an officer of the company, a Liscenced Professional Engineer or Professor for student entries, attesting to the cylinder compressive strength, the fact that the competition rules as out lined in this document were followed, and the slump air and unit weight of the concrete.
   
   
8. At the time of breaking, a digital video will be produced. This video can be as simple or as complicated as desired but shall show the cylinder in the compression machine and the final breaking load and should be no more than approximately one minute in length unless more is required to show the break. Creativity is encouraged but not required. A Google Drive may be set up to receive these videos. Contact Lisa Lukefahr for details.
   
   
9. Concrete constituent materials ARE limited to those available within the state of Texas. In the interest of information sharing friendly competition, TACA recommends and requests the technical data for mix constituents, but allows participants the choice in divulging proprietary information.
   
   
10. Portland cement Type I or II up to 200 pounds per yard in the mix design. The total cementious amount is limited to 700 pounds. Admixture dosage, pozzolanic replacement, minimum or maximum slumps, air content, water content, etc. should be recorded on the submittal for the contest.
    
    
11. Only one submission (results from one 4in x 8in cylinders) per TACA member/ student is permitted.
    
    
12. Rule clarification questions should be submitted in writing via e-mail to Chair of the Specification Committee, Michael Whisonant at michael.whisonant@martinmarietta.com .
    
    
13. Winners will be announced later this summer, receive awards and bragging rights.

I do hereby certify that the cylinder used in the 2020 TACA Sustainability & Strength Concrete competition was cast on the following date and was of age 3 days +/- 6 hours and 28 days +/- 24  hours at the time of testing and had been cast and cured according to the rules laid out by TACA for this competition.