Water-reducing admixtures reduce the quantity of water required to produce concrete of a certain slump. They also: Reduce the water-cement ratio Reduce cement content increase slump Typically, water reducing admixtures reduce the water content by approximately 5 – 10% for the same strength properties. Effect on Strength Generally, an increase in strength is obtained with […]
Air Entraining Admixtures
Air entraining admixtures, as you can probably guess, force air into the concrete. They result in microscopic air bubbles spread relatively evenly throughout the concrete. Reasons for Using Air Entraining Admixtures There are several reasons to have air entrainment in concrete: To improve freeze-thaw resistivity To increase resistance to de-icing chemicals To enhance the workability […]
Types of Concrete Admixtures
Admixtures are used in almost any concrete mixture produced today. Following is a list of the most common ones: Accelerators When you need fast strength gain because other components require construction adjacent to the concrete. Accelerating admixtures shorten the setting and early-strength development time. They consist of Calcium chloride, Triethanolamine, sodium thiocyanate, calcium formate, calcium […]
Concrete Strength Factors
The compressive strength of concrete is expressed in Megapascals (MPa) or pounds per square inch (psi) at an age of 28 days. Since the strength is constantly increasing, the reference strength chosen by industry is 28 days. Typical strengths are in the range of 25 – 35 MPa (3,600 – 5,000 psi). On my bridge […]