1. Configuration strength C1=C+1.645&.(&is the standard deviation, generally 5. That is to say, C30 concrete configuration strength is generally 38-40mpa) 2 Determine the water cement ratio: W/c=0.45 * f/C1 (f is the actual strength of cement) 3. Water consumption: 160-175kg according to experience 4. Calculate the required volume of aggregate by volume method 5. The sand ratio is 38-42%,
