The use of concrete admixtures

In the construction project, the use of concrete admixtures and concrete is a crucial link. In order to ensure the construction quality and structural safety, we need to pay attention to the following matters.

For Concrete:

• Avoid the use of coal ash: clean concrete should not be mixed with coal ash, so as not to affect the color and appearance of the concrete consistency.

• The aluminum content in the sand should be strictly controlled, because aluminum will have an adverse effect on the color of the concrete, making the color of the exposed concrete uneven.

For Admixtures:

• Air entrainment selection: Avoid using saponifiables and K series air entrainment agents as they may affect the performance of the concrete. On the contrary, air entraining agents for polymer synthesis can be selected.

• Use of defoamer: While defoamer helps eliminate air bubbles in concrete, it is not necessary. It is important to expel the gas to ensure the compaction of the concrete.

• Ensure workability: admixtures should ensure the workability of concrete, so that concrete is easy to operate in the construction process and improve construction efficiency.

• Relevance to concrete design: The selection and use of admixtures is closely related to concrete design. Appropriate admixtures should be selected according to the design requirements to meet the strength and durability requirements of the structure.

• Surface repair admixtures of exposed concrete: there are surface repair admixtures of exposed concrete on the market at present, and the effect is good. This kind of admixture can be used to repair the defects of concrete surface and improve the flatness and appearance of the surface.

To sum up, the use of fair-faced concrete and admixtures involves many precautions, from the selection of raw materials to the determination of construction technology, each link needs to be carefully controlled to ensure that the final quality and appearance of fair-faced concrete to achieve the desired effect.