3305.3.2.3 Lateral concrete pressure.
BC § 3305.3.2.3
Design of forms, ties and bracing shall satisfy the minimum lateral pressures of fresh concrete specified in Table 3305.3.2.3. Maximum rate of placement shall be shown on the design drawings. Table 3305.3.2.3Minimum Lateral Pressures to be Assumed for Fresh Concrete Weighing 150 Pounds Per Cubic Foot a, b, c Type of Work Minimum Lateral Pressure Assumed (psf)Limitations Columns: Ordinary work withnormal internal vibrationp = 150 + (9000R/T) Maximum 3,000 psf or 150h,whichever is lessWalls: Rate of placement at7 feet per hour or lessp = 150 + (9000R/T) Maximum 2,000 psf or 150h,whichever is lessWalls: Rate of placement atgreater than 7 feet per hourp = 150 + (43400/T) + (2800R/T)Maximum 2,000 psf or 150h,whichever is lessSlabs p = 150h None For SI: 1 inch = 25.4 mm, 1 foot per second = 0.305 m/s, 1 pound per cubic foot = 16.02 kg/m 3 , 1 pound per square foot = 4.882 kg/m 2 , °C = (°F-32)/1.8. where: R = rate of placement, feet per hour. T = temperature of concrete in the forms, °F. h = height of fresh concrete above point considered, feet. a. Allowances for change in lateral pressure shall be made for concrete weighing other than 150 pcf; for concrete containing pozzolanic additions or cements other than Type I, for concrete having slumps greater than 6 inches, or for concrete consolidated by revibration or external vibration of forms. b. Where retarding admixtures are employed under hot weather conditions, an effective value of temperature less than that of the concrete in the forms shall be used in the above formula. c. If retarding admixtures are used in cold weather, the lateral pressure may be assumed as that exerted by a fluid weighing 150 pcf.
