Mortar is a vital building material that is used in the construction industry for various purposes, such as bricklaying, concrete repair, and block filling. It comprises of cement, sand, water, and other admixtures that enhance its properties. One such admixture is the air-entraining agent, which is added to mortar to create tiny air bubbles throughout the mixture. In this article, we will discuss the function of air-entraining agent in mortar.

Introduction Mortar is a combination of cement, sand, water, and other admixtures that is used in construction. The primary function of mortar is to bond building blocks, such as bricks, stones, and concrete blocks, together to form walls, foundations, and other structures. However, mortar can be vulnerable to various problems, such as cracking, freezing, thawing, and erosion. These problems can weaken the mortar and affect the structural integrity of the building. One way to address these problems is to add an air-entraining agent to the mortar.

What is an Air-Entraining Agent? An air-entraining agent is a chemical admixture that is added to mortar to create tiny air bubbles throughout the mixture. The air bubbles are evenly distributed and form a network of small voids within the mortar. The air-entraining agent can be in liquid or powder form and is typically added to the mixing water before adding the cement and sand.

Function of Air-Entraining Agent in Mortar The addition of an air-entraining agent to mortar provides several benefits, including:

1. Improved Freeze-Thaw Resistance: One of the primary benefits of air-entraining agent is that it improves the freeze-thaw resistance of mortar. The tiny air bubbles in the mortar act as a buffer against the expansion and contraction caused by freezing and thawing. Without the air-entraining agent, the water inside the mortar would freeze and expand, causing the mortar to crack and weaken. The air-entraining agent prevents this by allowing the water to expand into the tiny air bubbles, preventing the formation of large cracks and maintaining the structural integrity of the mortar.
2. Improved Workability: Another benefit of air-entraining agent is that it improves the workability of the mortar. The air bubbles in the mortar act as a lubricant, making it easier to mix and spread. This, in turn, makes the mortar easier to apply and ensures that it can be spread evenly over the surface of the building blocks.
3. Increased Durability: Air-entraining agent can also increase the durability of mortar. The tiny air bubbles in the mortar help to reduce water absorption, which can cause damage to the mortar over time. By reducing water absorption, the air-entraining agent can help to prevent the mortar from eroding, cracking, or otherwise deteriorating.
4. Improved Strength: Finally, air-entraining agent can improve the strength of the mortar. The tiny air bubbles in the mortar help to distribute the stress evenly across the mixture, which can help to prevent cracks and other damage. This, in turn, can help to ensure that the mortar retains its structural integrity and provides a reliable bonding agent for building blocks.

Conclusion In conclusion, the addition of an air-entraining agent to mortar provides several benefits, including improved freeze-thaw resistance, improved workability, increased durability, and improved strength. These benefits can help to ensure that the mortar retains its structural integrity, even in challenging environments. As such, air-entraining agents are an important component of modern construction and should be considered for any building project where mortar is used.