Polyvinylpyrrolidone (PVP), a water-soluble polymer, has demonstrated significant application value in the field of concrete materials due to its unique physicochemical properties. It can optimize the overall quality of concrete from multiple dimensions, including improving workability, enhancing mechanical properties, and improving durability.

During the concrete mixing stage, PVP's water solubility and surface activity enable it to play a highly efficient dispersing and plasticizing role. The polar groups on the PVP molecular chain can adsorb onto the surface of cement particles, forming a steric hindrance effect that hinders the aggregation of cement particles, thereby effectively reducing the water demand of the concrete mixture and improving its fluidity and workability. For high-grade concrete or self-compacting concrete, adding an appropriate amount of PVP can ensure good pumpability and filling properties of the mixture without increasing the water-cement ratio, reducing problems such as pipe blockage and segregation during construction, and is particularly suitable for casting complex structures or thin-walled components.

In terms of enhancing mechanical properties, PVP can improve the strength and toughness of concrete by regulating the cement hydration process. On the one hand, PVP's adsorption effect can slow down the early hydration rate of cement, avoiding internal microcracks caused by concentrated release of hydration heat, while promoting the uniform distribution of later hydration products and optimizing the microstructure of cement paste. On the other hand, PVP molecular chains can form a flexible network within the cement paste, filling capillary pores and bridging microcracks, thus enhancing the flexural strength and impact resistance of concrete. Studies have shown that within a reasonable dosage range (typically 0.1%–0.5% of the cementitious material mass), PVP can increase the 28-day compressive strength of concrete by 5%–15% and the flexural strength by 10%–20%, significantly improving its brittle characteristics.

PVP also demonstrates outstanding performance in the field of durability improvement. Firstly, PVP's film-forming properties allow it to create a dense hydrophobic film within concrete, blocking capillary pores and reducing porosity and water absorption. This inhibits the intrusion of corrosive media such as chloride ions and sulfates, delaying steel corrosion and chemical corrosion of concrete, thus extending the service life of the structure. It is particularly suitable for concrete projects in harsh environments such as coastal areas and saline-alkali lands. Secondly, PVP's stabilizing effect on cement hydration products reduces the probability of alkali-aggregate reaction, preventing cracking due to volume expansion and improving long-term stability. Furthermore, PVP enhances the freeze-thaw resistance of concrete by improving pore structure and lowering the freezing point, reducing the damage caused by pore water freezing and expansion during freeze-thaw cycles, significantly improving its applicability in cold regions.

It is important to note that the dosage of PVP must be strictly controlled. Excessive addition can delay hydration due to the excessive encapsulation of cement particles by the molecular chains, leading to a decrease in the early strength of concrete and increasing material costs. Furthermore, the compatibility of PVP with other admixtures (such as water-reducing agents and air-entraining agents) needs to be verified in advance to ensure synergistic effects of various components and avoid compatibility issues. With the increasing demand for high-performance concrete, the modification potential of PVP in specialty concretes (such as ultra-high performance concrete and intelligent self-healing concrete) will be further explored, providing new technological pathways for the upgrading of concrete materials.

PENGFEI is a company dedicated to the research, production, and sales of 2-pyrrolidone (2-P), N-vinylpyrrolidone (NVP), and polyvinylpyrrolidone (PVP)