1EA102 American Concrete Association (ACI) Absolute Volume Method of Concrete Mix Design EXAMPLE ACI MIX DESIGN Mix Component Properties: Cement Type: 10 Specific Gravity: 3.155 Coarse Aggregate Nominal Maximum Particle Size: 10 mm SSD Bulk Specific Gravity: 2.660 % Absorption Capacity: 3.50% Dry-Rodded Density: 1.530 Mg/m 3 Fine Aggregate SSD Bulk Specific Gravity: 2.700 % Absorption Capacity: 1.50% Fineness Modulus: 2.700 Desired Mix Properties: A 30 kg batch on non-air-entrained concrete with a slump in the 80 to 100 mm range and a water/cement ratio of 0.5 is required. SOLUTION: 1. Determine densities of all materials to be used: ρ = G x ρ w Material Specific Gravity x ρ w = Density (kg/m 3 ) Water 1.0 x 1000 = 1000 Cement 3.155 x 1000 = 3155 SSD Fine Aggregate 2.700 x 1000 = 2700 SSD Coarse Aggregate 2.660 x 1000 = 2660 Dry-Rodded Coarse Aggregate 1530 2. Mass of mixing water in 1 m 3 of mix = 228 kg = 0.228 m 3 (Table 4a for non-air-entrained, Nominal Maximum size = 10mm and slump between 80 & 100 mm) 3. Volume of air in 1 m 3 of mix is 3.00% of 1 m 3 or 0.030 m 3 (Table 4c for non-air-entrained, Nominal Maximum size = 10mm) 2 4. kg 456 0.5 kg 228 0.5 w c then 0.5, c w If The mass of cement required = 456 kg The volume of cement 3 kg/m 3155 kg 456 The volume of cement required = 0.145 m 3 5. Volume of dry-rodded coarse aggregate = 0.47 m 3 (Table 3 for Nominal Maximum size = 10 mm and fineness modulus of 2.70) 6. SSD mass of coarse aggregate = 0.47 m 3 x 1530 kg/m 3 = 719 kg SSD volume of coarse aggregate 3 kg/m 2660 kg 719 = 0.270 m 3 7. Sum of known volumes = (0.228 + 0.030 + 0.145 + 0.270) m 3 = 0.673 m 3 SSD volume of fine aggregate = 1 – 0.673 m 3 = 0.327 m 3 SSD mass of fine aggregate = 0.327 m 3 x 2700 kg/m 3 = 883 kg 8. Total mass of 1 m 3 of mix = (228 + 456 + 719 + 883) kg = 2286 kg/m 3 The proportioning factor kg 30 kg 2286 = 76.2 Each mass for the 1 m 3 of mix is then divided by this factor: Materials Mass (kg/m 3 ) Volume (m 3 ) SSD Mix Masses (kg) Cement 456 0.145 5.984 Water 228 0.228 2.992 Coarse Aggregate 719 0.270 9.436 Fine Aggregate 883 0.327 11.588 Air 0.030 Totals 2286 1.000 30.000 NOTE: The information in this table should appear in the table on Datasheet 7.5. Do not present it twice!