How to Calculate Water to Cement Ratio's A low water to cement ratio is the number one issue effecting concrete quality. Use a maximum .50 water to cement ratio when concrete is exposed to freezing and thawing in a moist condition or to deicing chemicals per the 1997 Uniform Building Code. Water permeability increases exponentially when concrete has a water cement ratio greater than .50.
Durability increases the less permeable the concrete mix is.
Strength improves with lower water cement ratios. A .50 water cement ratio will likely reach 4000 psi or greater. For complete Uniform Building Code information regarding concrete construction, review with your architect, your ready mix supplier, or at your local library. If the mix lists the water in gallons, multiply the gallons by 8.33 to find how many pounds there are in the mix. Content provided by the Concrete Network .