Concrete additive is an admixture added during concrete mixing. It is mainly used to improve the performance of concrete. From the point of addition ratio of admixture, generally not more than 5%.
For all kinds of concrete admixtures, the role of the precipitant is mainly to reduce the water consumption, increase the density and elasticity of the concrete, and make the concrete durable. The air entraining agent can improve the solubility of the concrete, and reduce the internal crack of the concrete by improving the internal structure of the concrete, so that the concrete can improve its antifreeze and impermeability. For concrete with high frost resistance requirements, it is possible to properly perform bleed air or a mixture of precipitation additives. For concrete with higher impermeability requirements, the density of concrete must be increased by high-performance precipitation agents. At the same time, the use of air entraining additives to reduce the occurrence of water seepage, improve the impermeability of the building structure. In addition, considering the corrosive phenomenon of steel bars in concrete, the use of precipitation agents can effectively reduce the carbonization rate of concrete. Once the pH in the concrete drops, the rust of the steel will also decrease. For the use of various types of concrete admixtures, it is necessary to make a correct choice in combination with different concrete performance requirements, and to achieve the greatest improvement in concrete performance through scientific proportional control. The bleed air admixture is used for the improvement of concrete performance.
Adding a certain proportion of bleed air admixture to the concrete can create many independent bubbles inside the concrete. These bubbles can improve the solubility of concrete, increase the slump of concrete, and reduce its bleeding. For the addition of the air entraining agent, the control of the concrete setting time can be controlled by the scientific proportional addition control. Under certain conditions, the air entraining agent will also reduce the strength of the concrete, causing precipitation and increasing the strength of the concrete. This is mainly because the air entraining agent can cause many bubbles to form inside the concrete. This requires that the use of bleed air admixtures should be clearly selected based on different concrete performance requirements. The traditional way of using concrete can not save the amount of use, which is not conducive to the control of construction cost. Through the use of concrete admixtures, the improvement of various aspects of concrete performance can be achieved, and the amount of concrete used can be reduced to some extent. This has contributed to the development of energy-saving performance of concrete.
Adverse effects on the performance of concrete, concrete admixtures have certain adverse effects while improving the performance of concrete. For example, when the amount of admixture added is not scientific, the performance of concrete is greatly reduced. When the amount of the common retarder is too much, the concrete will not be aggregated for a long time, and on the other hand, the molding effect of the concrete is affected. On the other hand, it is not conducive to the improvement of concrete strength This will bring some engineering quality hazards. In addition, when using various types of admixtures simultaneously, due to the amount of control used. Improper or not taking into account the mutual reaction between the admixtures may result in a chemical reaction between the additives. This is not conducive to the improvement of concrete performance.
All in all, concrete is the main material in construction. To be sure, keep its performance in line with building requirements. It is necessary to strictly control the use of external additives. Improve the structural stability of the building by optimizing the performance of the concrete. This makes concrete additives play an important role in the construction industry. China should strengthen the performance development of external additives, learn from each other's strengths, and use additives as an important building supporting technology to play its due value in project implementation.