msesi, I would agree with Ron above, the 75-85% strength at seven day is a specification for stripping forms, and preloading (IBC). second - the average f'c is calculated with three samples broke at 28 day with no single break falling below design by more than 500 psi, ASTM C 39, ACI 318. The...
Has any one used ASTM C 1688 for testing pervious concrete? what are your thoughts about perviouse concrete? Has ASTM / ACI helped anyone with pervious concerte? I am getting my information to gather before taking all of my informastion to the ASTM C.09 Committee. Thank you in advance.
I want to thank all of you for your input on this problem. I have used your imput and forwarded it on to the QA Manager for his report. Thank you again for your assistance.
The cube is cast with 2000 psi grout, area is 3.97 sqI, and it is loaded between the 2" riser and head @ a rate of 300 lb per minute. the 7 day results are 27560 load, 6940 psi. The 28 day results are, 22965 load, 5780 and 27695 load, 6980
With a 2" x 2" cube and design strength of 2000 psi @ 28 day. The results for the 7 day comressive strength is higher. I have reviewed the test methodes and innitial curing procedures. I cannot find the reason for these results can some one assist, explane the reason or direct me to the answer.