PORTLAND CEMENT CONCRETE - Materials for Civil and Construction Engineers - page 251

0.107 yd 3 V cement = 567.4/ 1 3.15 * 1684.8 2 =

0.145 yd 3 V water = 244/1684.8 =

0.474 yd 3 V gravel = 2077/ 1 2.6 * 1684.8 2 =

Subtotal

0.040 yd 3 V air = 4 % =

0.766 yd 3 =

0.234 yd 3 V sand = 1 - 0.766 =

946 lb/yd 3 m sand = 1 0.234 21 2.4 21 1684.8 2 =

Step 10: mix water = 244 - 2077 1 0.023 - 0.045 2 - 946.2 1 0.022 - 0.017 2

285 lb/yd 3 =

2125 lb/yd 3

moist gravel = 2077 1 1.023 2 =

967 lb/yd 3 moist sand = 946.2 1 1.022 2 =

567 lb/yd 3

cement =

air entrainer = 2.27 fl. oz

Sample Problem 7.4

Design a concrete mix for the following conditions and constraints using the absolute
volume method:

Design Environment
Bridge pier exposed to freezing and subjected to deicing chemicals
Required design strength = 24.1 MPa (3500 psi)

Minimum (12 in.)
Minimum space between (2 in.)
Minimum cover over (1.5 in.)
Standard deviation of compressive strength of 2.4 MPa (350 psi) is expected
(more than 30 samples)
Only air entrainer is allowed

dimension = 0.3 m

rebars = 50 mm

rebars = 40 mm

Available Materials
Cement
Select Type V due to exposure
Air Entrainer
Manufacturer specification 6.3 ml/1% air/100 kg cement (0.1 fl oz/1% air/100 lb
cement)
Coarse aggregate
25 mm (1 in.) maximum size, river gravel (round)
Bulk oven dry specific gravity

= 2.621, Absorption = 0.4 %