Water Cement Ratio

-Compressive &Tensile strength and most of the other desirable properties of concrete is inversely related to w/c ratio

-Low w/c ratio increases freeze thaw resistance & decreases shrinkage

-Minimum amount of water is required to completely hydrate the cement (0.27-0.32)

- 0.65 - 0.7 onward - Less Strength

Compressive Strength, psi(MPa)	w/c Ratio By Weight
6000 (41)	0.41
5000 (34)	0.48
4000 (28)	0.57
3000 (21)	0.68
2000 (14)	0.82

-Strength is based on 6”x12” cylinders, moist cured, 28 days at 23+-2C in accordance with section 9B of ASTM C31