Post Date:13,Sep,2022
Significant technical and economic benefits of air-entraining agent used in commercial concrete
Air-entraining admixture is an admixture that can produce a large number of tiny, dense and stable bubbles when mixed into concrete. Durability such as frost resistance and impermeability. The addition of air-entraining agent to commercial concrete can prevent the secondary adsorption of dispersed cement particles in the concrete and improve the slump retention performance of commercial concrete. At present, air-entraining agent is one of the indispensable components in commercial concrete admixture (others are water reducer and retarder). In Japan and western countries, there is almost no concrete without air-entraining agent. In Japan, concrete without air-entraining agent is called special concrete (such as permeable concrete, etc.).
Air-entraining will affect the strength of concrete, which refers to the test results under the condition of concrete and water-cement. When the air content increases by 1%, the strength of concrete will be reduced by 4% to 6%, and the addition of air-entraining agent will also reduce the strength of concrete. The water rate is greatly increased. It has been tested with naphthalene-based superplasticizer. When the concrete water reduction rate is 15.5%, the concrete water reduction rate reaches more than 20% after adding a very small amount of air-entraining agent, that is, the water reduction rate increases by 4.5%. For every 1% increase in water rate, the concrete strength will increase by 2% to 4%. Therefore, as long as the amount of air-entraining
agent is strictly controlled, not only the strength of concrete will not decrease, but it will increase. For the control of air content, many tests have shown that the air content of low-strength concrete is controlled at 5%, the medium-strength concrete is controlled at 4% to 5%, and the high-strength concrete is controlled at 3%, and the concrete strength will not be reduced. . Because the air-entraining agent has different effects on the strength of concrete with different water-cement ratios.
Considering the water-reducing effect of air-entraining agent, when preparing commercial concrete admixture, the mother liquid of water-reducing agent can be greatly reduced, and the economic benefit is considerable.
Post time: Sep-14-2022