i wouldnt pour a four in. driveway, so at six in. you will need eleven 1/4 yds. of 3500 lb. mix with fiber and air added… Reply
20′ x 30′ x 4 = 7.4 cubic yards
20×30=600 total feet
600/80=7.5 yards of concrete
20 x 30= 600 x .33=198/ 27=7.33 yds
i wouldnt pour a four in. driveway, so at six in. you will need eleven 1/4 yds. of 3500 lb. mix with fiber and air added…