At 7 days your concrete will have reached around 70 of its. Ad Level Sunken Concrete With a Quick Clean Long-Lasting Solution. Civil Engineering On Instagram Subscribe Our Youtube Channel Link In Bio Follow Me Civil Engineers 07 Civil Engineering Grade Of Concrete Engineering Quick Effective and Long-Lasting Solutions To Lift Your Sunken Concrete. . Compare expert Concrete Repair read reviews and find contact information - THE REAL YELLOW PAGES. Local Concrete Repair in Bayonne NJ. Which test is most suitable for concrete strength. However it would certainly depends upon no of factors such as- type of. Concrete by Mindness and Young gives a general rule. A concrete cube test. The ratio of 28-day to seven-day strength lies between 13 and 17 and generally is less than 15 or the seven-day. The compressive strength acceptance is specified by 261231 of ACI 318-14 as. The 28 days concrete test results are accept...