test for fresh concrete

• Compressive strength s tested by pouring cylinders of fresh concrete and mesuring the force needed to break the concrete cylinders a t proscribed intervals a s they harden .
• According to Building code Requirements for Reinforced Concrete ( ACI 318 ) , as long as no single test is more than 500 psi below the design strengh then the concrete is acceptable . If the strength tests don;t meet these criteria , steps must be taken to raise the average.