In: Civil Engineering
Q1) Designa concrete mixture proportions which will be used for offshore concrete platform.Norway is a world leader on offshore concrete platforms with 7 of the world’s 30 larger offshore concrete structures located on the Norwegian continental shelf. The first of these platforms where the Ekofisk Tank installed in 1974 and the last was Troll gravity based structure installed in 1996. The Sakhalin project is located in a harsh and artic environment where concrete structures have proven excellent characteristics with a minimum of maintenance. 80 mm slump value is required for the Sakhalin project. 28-days concrete characteristic strength is 8 MPa. It is required that no more than 1 test result in 100 will fall below the specified strength. The fine aggregate has a fineness modulus of 2.60 and Zone 3. For Coarse Aggregate (Uncrushed):SSD Bulk Specific Gravity: 2.65, Absorption Capacity: 2.4%, Total Moisture: 1.4% and Dry Rodded Unit Weight: 1345 kg/m3. For Fine Aggregate (Uncrushed):SSD Bulk Specific Gravity: 2.70, Total Moisture: 3.4% and Free Moisture: 2 %. Cement: Portland Composite Cement, Specific Gravity: 2.97. For 0.5 m3of concrete, binder amount is calculated as 120 kg(Use ACI Method of Mix Design)
ACI method of mix design and final mix proportion of concrete after moisture adjustments for the given specification is shown below.