Aci Mix Design Method Example 6as4q

EA102

American Concrete Association (ACI) Absolute Volume Method of Concrete Mix Design

EXAMPLE ACI MIX DESIGN Mix Component Properties:

Cement

Coarse Aggregate

Fine Aggregate

Type: 10 Specific Gravity: 3.155 Nominal Maximum Particle Size: SSD Bulk Specific Gravity: % Absorption Capacity: Dry-Rodded Density:

10 mm 2.660 3.50% 1.530 Mg/m3

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 ρw Specific Material x ρw = Gravity Water 1.0 x 1000 = Cement 3.155 x 1000 = SSD Fine Aggregate 2.700 x 1000 = SSD Coarse Aggregate 2.660 x 1000 = Dry-Rodded Coarse Aggregate 2.

Mass of mixing water in 1 m3 of mix = 228 kg = 0.228 m3

Density (kg/m3) 1000 3155 2700 2660 1530

(Table 4a for non-air-entrained, Nominal Maximum size = 10mm and slump between 80 & 100 mm)

3. Volume of air in 1 m3 of mix is 3.00% of 1 m3 or 0.030 m3 (Table 4c for non-air-entrained, Nominal Maximum size = 10mm)

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4.

228 kg w w  0.5, then c    456 kg The mass of cement required = 456 kg c 0.5 0.5 456 kg The volume of cement  The volume of cement required = 0.145 m3 3 3155 kg/m If

5. Volume of dry-rodded coarse aggregate = 0.47 m3

(Table 3 for Nominal Maximum size = 10 mm and fineness modulus of 2.70)

6. SSD mass of coarse aggregate = 0.47 m3 x 1530 kg/m3 = 719 kg SSD volume of coarse aggregate



719 kg 2660 kg/m 3

= 0.270 m3

7. Sum of known volumes = (0.228 + 0.030 + 0.145 + 0.270) m3 = 0.673 m3 SSD volume of fine aggregate = 1 – 0.673 m3 = 0.327 m3 SSD mass of fine aggregate = 0.327 m3 x 2700 kg/m3 = 883 kg 8. Total mass of 1 m3 of mix = (228 + 456 + 719 + 883) kg = 2286 kg/m3 The proportioning factor 

2286 kg 30 kg

= 76.2

Each mass for the 1 m3 of mix is then divided by this factor: Mass (kg/m3)

Volume (m3)

SSD Mix Masses (kg)

Cement Water Coarse Aggregate Fine Aggregate Air

456 228 719 883

0.145 0.228 0.270 0.327 0.030

5.984 2.992 9.436 11.588

Totals

2286

1.000

30.000

Materials

NOTE: The information in this table should appear in the table on Datasheet 7.5. Do not present it twice!

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