Causes Of Bubbles in Concrete

In the process of cement production, the use of grinding AIDS, usually will produce too many bubbles, and the cement alkali content is too high, the cement fineness is too fine, the gas content will also increase. The amount of cement and water used are also important reasons for bubbles. In the concrete test match mainly for strength and consider the amount of cement, if in the premise of meeting the strength of concrete, increase the amount of cement, so as to reduce the water cement ratio, the amount of bubbles will be greatly reduced. The effect is to use the excess mortar to fill the remaining void, thus preventing the bubble from forming space.

If the concrete contains large bubble especially much, usually may be with admixture in air entraining composition is poor. General water reducing agent or compound pumping agent may be mixed with a certain air entrainment component of air entrainment agent, water reducing agent dosage increases, bubbles will also increase.

According to the principle of aggregate gradation is close-grained, in the process of construction, material gradation is unreasonable, coarse aggregate, size, the more the needle flake particle content is too much, actually used in the process of the production and sand ratio than the small sand ratio, the laboratory such fine grained, not enough to fill the coarse material gap leads to aggregate is close-grained, not the formation of free space, provides conditions for the generation of air bubbles.