What is air entrainment of concrete mixture?
Air entrainment: Air entrainment is an effective way of protecting concrete from freezing and thawing damage. It is achieved by adding a surface active agent in very small dosages to the concrete mixture. This action creates a large number of small, closely spaced air bubbles in the hardened concrete.
What is Vinsol resin?
Vinsol® resin is a dark reddish-brown, high melting, thermoplastic natural resin extracted from pinewood stumps and refined through a special process. Vinsol resin is produced exclusively by Pinova, Inc. in Brunswick, Georgia, USA.
Does air entrainment affect segregation?
Air-entraining agents can also reduce the surface tension of a fresh cement composition at low concentration, increase the workability of fresh concrete, and reduce segregation and bleeding.
What is the difference between air-entrained and non air-entrained concrete?
The water content for an air-entrained mix will be 3 to 5 gallons per cubic yard less than for a non-air-entrained mix having the same slump. The sand content will also be less by about 90 to 125 pounds per cubic yard. As for climate, air-entrained concrete is recommended and used considerably in southern climates.
When should you not use air entrained concrete?
4.1 Air-entraining agents should not be used in floors that are to have a dense, smooth, hard troweled surface. 6.2. 7 An air entraining agent should not be specified or used for concrete to be given a smooth, dense, hard-troweled finish because blistering or delamination may occur.
Is air entrained concrete stronger than non air entrained concrete?
These small bubbles give protection against freeze-thaw. Concrete with entrained air will have a lower strength than the same mix without entrained air, but the concrete can attain strengths required for most purposes by an increase in the cementitious factor of the mix or by reducing the water content.
What are common effects of using an air-entraining admixture in concrete?
Effects on Concrete Properties — Air entrainment increases the workability of fresh concrete. The tiny bubbles in the cement act like fine aggregates and reduce the interactions between solid aggregates. The improvement in workability leads to use of air entrainment admixtures even when freeze-thaw is not a problem.
What is the typical diameter of air entrained voids?
6.2.2 Entrained Air Voids Entrained air voids are generally considered to be larger than the capillaries (at least 5 µm in diameter) but smaller than the voids considered to be entrapped voids (Verbeck, 1966, 1978).
Where do you use air-entrained concrete?
It is beneficial to use air entrained concrete when placing concrete in areas with freeze-thaw conditions. Freeze-thaw conditions occur when the temperature of an environment fluctuates between above freezing temperatures and below freezing temperatures.