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Q: I have a question regarding the testing procedures in ASTM 109.  It specifies that the load rate will be between 12xxx and 22xxx lbs/min.  Could you specify an exact load rate that will be used in the competition?
A: Not exactly.  The judges will try to maintain a loading rate in the middle of the ASTM specified range.  However, throughout the loading history, the rate will fluctuate some within the prescribed range as the specimen "softens" due to microstructure crack development and propagation.
Q: Will there be neoprene padding used in the competition to reduce point loading?
A: No neoprene pads will be used.  When producing the cubes, the competition teams should try to produce cubes that have a flat surface to avoid any effects due to an uneven loading of the specimen's surface.
Q: What is the rate of applying the load (inkN/sec) to the samples?
A: See ASTM C 109 for the loading rate and testing method. To determine the appropriate testing time, take the ultimate strength in labs and divide by loading rate (lbs/sec) specified in ASTM C 109.
Q: Are we allowed to have random metallic particles such as iron fillings in our aggregate?
A: Iron fillings are not allowed. See Section 2b in the rules for allowable materials.
Q: I don’t understand at all if the cubes are able to have some entrapped air or entrained air?
A: All concrete or mortar has some entrapped air that is caused naturally during the batching or mixing process so entrapped air will occur naturally and is ok within the framework of this competition. However, the use of any entraining air admixtures is NOT allowed in this competition. If it is determined that an air-entraining admixture has been used, the cube and team will be disqualified.
Q: Does the air content have a maximum or minimum for this competition?
A: There is no air content maximum or minimum, but again, no air-entraining admixtures may be used in this competition.
Q: In the compression test, do you use any cushion or something similar? Or is it that the cube will just be in contact with the compression tester metal? Or will it have any special complement to unify the charge applied over the cube’s area?
A: The compression test should conform to ASTM C 109. In this test method the cube will be tested directly against the steel platen of the testing machine. To have uniform loading against the platen, it is advisable for the cube to naturally have a uniform smooth flat surface.