During the molding process of concrete, various factors such as materials, processes, and environmental conditions often lead to the formation of bubbles on the surface of the concrete.
A small amount of bubbles will not have a significant impact on components or buildings, but too many bubbles will bring a series of problems.
(When the air content of concrete increases by 1%, the compressive strength at 28 days decreases by 5%.
– Taken from Baidu Scholar).