Mortar

Mortar is a fundamental material used in construction for various purposes such as brickwork, masonry, plastering, and pointing. It is a mixture of binders, aggregates, and water that provides strength, durability, and workability to structures. In this article, we will explore the properties and uses of mortar.

Properties of Mortar

Mortar possesses several important properties that determine its suitability for different applications.

Composition of Mortar

The composition of mortar consists of three main components:

1. Binders: Binders are materials that hold the aggregates together. Common binders include cement, lime, and gypsum.
2. Aggregates: Aggregates are inert materials such as sand, crushed stone, or gravel that provide bulk and stability to the mortar.
3. Water: Water is added to the mixture to activate the binders and facilitate the hydration process.

Workability of Mortar

The workability of mortar refers to its ability to be easily mixed, placed, and compacted. It is influenced by three factors:

1. Consistency: Consistency refers to the fluidity or stiffness of the mortar. It can be adjusted by controlling the water content.
2. Plasticity: Plasticity is the ability of the mortar to retain its shape without cracking or sagging. It is influenced by the type and proportion of binders used.
3. Cohesion: Cohesion refers to the ability of the mortar to stick together and resist segregation. It is influenced by the fineness and grading of the aggregates.

Strength of Mortar

The strength of mortar is crucial for ensuring the structural integrity of buildings. It can be classified into three types:

1. Compressive strength: Compressive strength is the ability of mortar to withstand axial loads or pressure. It is determined by the type and proportion of binders and aggregates used.
2. Tensile strength: Tensile strength is the ability of mortar to resist tension or pulling forces. It is generally lower than the compressive strength and can be improved by adding reinforcing fibers or admixtures.
3. Flexural strength: Flexural strength is the ability of mortar to resist bending or flexing. It is important for structures subjected to lateral loads or vibrations.

Durability of Mortar

Durability is a critical property of mortar as it determines its resistance to weathering, chemical attack, and abrasion. The following factors contribute to the durability of mortar:

1. Resistance to weathering: Mortar should be able to withstand exposure to various climatic conditions without significant deterioration. It should resist the effects of freezing and thawing, moisture penetration, and temperature changes.
2. Resistance to chemical attack: Mortar should be resistant to chemical substances present in the environment, such as acids, alkalis, and salts. This is particularly important in industrial or coastal areas.
3. Resistance to abrasion: Mortar should have sufficient hardness and toughness to resist abrasion caused by mechanical forces or contact with other materials.

Uses of Mortar

Mortar has a wide range of applications in construction, including:

Brickwork and Masonry

Brickwork and masonry are the most common uses of mortar. Mortar is used for:

1. Construction of walls: Mortar is used to bond bricks or blocks together to form load-bearing walls.
2. Construction of arches: Mortar is used to create arches, which provide structural support and architectural appeal.
3. Construction of chimneys: Mortar is used to construct chimneys, ensuring their stability and preventing smoke leakage.

Plastering and Rendering

Mortar is used for plastering and rendering, which involves applying a layer of mortar to the interior or exterior surfaces of a structure. This serves the following purposes:

1. Interior plastering: Mortar is used to create a smooth and even surface on interior walls and ceilings, enhancing the aesthetics and providing a base for paint or wallpaper.
2. Exterior rendering: Mortar is used to protect the exterior walls from weathering and provide a decorative finish.
3. Decorative finishes: Mortar can be colored or textured to create decorative finishes, such as stucco or pebble dash.

Pointing and Repointing

Pointing and repointing involve repairing and maintaining the joints between bricks or stones. Mortar is used for:

1. Repairing and maintaining masonry joints: Mortar is used to fill gaps or cracks in the joints, ensuring the structural integrity of the masonry.
2. Improving the appearance of masonry: Mortar can be used to enhance the visual appeal of masonry by matching the color and texture of existing mortar.
3. Preventing water penetration: Mortar is used to create a watertight seal in the joints, preventing water from entering the structure.

Advantages and Disadvantages of Mortar

Mortar offers several advantages and disadvantages in construction:

Advantages

1. Provides strength and stability to structures: Mortar acts as a binding agent, holding the bricks or stones together and providing structural integrity.
2. Enhances the aesthetic appeal of buildings: Mortar can be colored, textured, or finished in various ways to enhance the visual appearance of buildings.
3. Offers protection against weather and environmental factors: Mortar provides a protective layer that shields the underlying materials from weathering, moisture, and chemical attack.

Disadvantages

1. Requires proper mixing and application techniques: Mortar should be mixed in the correct proportions and applied properly to ensure its effectiveness and durability.
2. Can deteriorate over time if not maintained properly: Mortar joints may deteriorate due to weathering, settlement, or lack of maintenance. Regular inspection and repair are necessary.
3. Limited load-bearing capacity compared to other construction materials: Mortar is not as strong as materials like concrete or steel and may have limitations in supporting heavy loads.

In conclusion, mortar is a versatile material that plays a crucial role in construction. Its properties and uses make it an essential component for various applications, ensuring the strength, durability, and aesthetics of structures.

Summary

Mortar is a fundamental material used in construction for various purposes such as brickwork, masonry, plastering, and pointing. It possesses properties like composition, workability, strength, and durability. Mortar is used in brickwork and masonry for constructing walls, arches, and chimneys. It is also used for plastering and rendering, decorative finishes, and pointing and repointing. Mortar offers advantages like providing strength and stability to structures, enhancing the aesthetic appeal, and offering protection against weather and environmental factors. However, it requires proper mixing and application techniques, can deteriorate over time if not maintained properly, and has limited load-bearing capacity compared to other construction materials.

Analogy

Mortar is like the glue that holds the pieces of a puzzle together. Just as the puzzle pieces need the glue to form a complete picture, the construction materials need mortar to form a strong and stable structure.