Sand is a vital and multipurpose natural material. Sand is used in various manufacturing and construction activities. It is made up of finely divided rocks and mineral particles, which have a range of properties of sand that make it important in diverse applications. The particle size, shape and composition of sand can differ greatly, influencing their behaviour and suitability for different uses.
The unique properties of sand, like its ability to compact under pressure and provide stability, make it an important ingredient in concrete, mortar and asphalt. Sand is a key component for construction, but it also affects soil health and coastal dynamics in environmental and geological contexts. This article discusses the technical properties of sand, like the physical and chemical properties of sand and highlights its role in the construction environment.
Types of Sand
Primarily six types of sand are used in construction, and each has unique features, advantages, and disadvantages. Let’s examine them briefly.
- River Sand: A naturally occurring sand that is collected from riverbeds and is popular for its smooth texture and high quality. The river sand’s chemical composition gives it very good strength and binding properties.
- M-Sand: M-sand, or manufactured sand, is sand that is made artificially by crushing hard granite stones. The properties of sand in construction make it a suitable substitute for river sand. It is known for its consistent qualities and environmental benefits.
- P-Sand: Sand specifically designed for plastering tasks is called plastering sand or P-sand, and it’s a fine-grade sand that guarantees a smooth wall finish and strong adhesion.
- C-Sand: Coarse sand also known as concrete sand, is added to concrete mixtures to give construction projects stability, strength and bulk.
- Filter Sand: To ensure a clean and safe water supply, filtration systems use this specially graded sand to remove impurities and contaminants from water.
- Bedding Sand: It serves as a bedding layer for laying paving stones, bricks, and other materials by providing an even and stable base.
Properties of Sand
Look at the properties of sand in construction that make it an ideal construction material.
1. Particle Size and Distribution
2. Shape and Texture
3. Composition
4. Adhesiveness
5. Cohesiveness
6. Density and Specific Gravity
7. Permeability and Porosity
8. Thermal Conductivity
Let’s have an overview of each of these properties of sand.
1. Particle Size and Distribution
(i) Grain Size
The diameter of sand particles ranges from 0.0625 mm to 2 mm. Sand can be divided according to size on the geological scale between silt, which has finer particles, and gravel, which has coarser particles. For a sand sample to be used in a particular application, the uniformity or gradation of particle sizes is an essential physical property of sand.
(ii) Gradation
Gradation is the distribution of various particle sizes within a sand sample. Sand that has been graded properly offers good compaction and stability, and it also has a range of particle sizes, which makes it perfect for construction. For applications demanding high permeability, sand with uniform particle sizes but poor grading is used.
2. Shape and Texture
(i) Grain Shape
There are four types of sand particle shapes, such as angular, sub-angular, rounded, and sub-rounded. Sharp-edged angular grains give construction materials greater interlocking and durability. In situations where smoother textures are beneficial, like playground sand, rounded grains with smooth surfaces are frequently chosen.
(ii) Surface Texture
Sand grains have two different surface textures: smooth and rough. Because they have more surface area for the binding agents to stick to, sands with a rough texture improve bonding in mortar and concrete.
3. Composition
(i) Mineral Content
Sand mainly consists of quartz (silicon dioxide, SiO2), which is known for its chemical stability and hardness, which is one of the core sand properties. However, depending on the source of the rock, sand can also contain other minerals like magnetite, feldspar, and mica.
(ii) Impurities
The quality of sand can be affected by impurities, like silt, clay, and organic matter. The strength and durability of the sand can be affected by high impurity levels in them.
4. Adhesiveness
The capacity of sand particles to stick to other materials is known as adhesiveness. This chemical composition of sand is important when sand is used with binding substances like cement or clay in manufacturing or construction processes. Adhesiveness affects concrete and mortar workability. The physical properties of sand, like the shape and surface texture of the grains of sand, also impact it.
5. Cohesiveness
Cohesive sand particles tend to bind together because of intermolecular interactions. This property of sand is necessary for sand’s stability and compaction in a variety of applications.
6. Density and Specific Gravity
(i) Bulk Density of Sand
The moisture content and level of compaction of sand affect the bulk density of sand. Wet sand can have a bulk density of up to 2000 kg/m³, but dry sand density is around 1600 kg/m³.
(ii) Specific Gravity
Generally, sand has a specific gravity of 2.60 to 2.80, which is the ratio of its density to that of water. Specific gravity is the core sand property and is vital for figuring out how much sand is needed for a specific mass.
7. Permeability and Porosity
(i) Permeability
The ability of sand to permit liquids to move through it is referred to as permeability. The permeability of poorly graded sand with uniform particle sizes is higher than that of well-graded sand with a range of particle sizes. Sand permeability is essential for uses such as water filtration and drainage systems.
(ii) Porosity
Porosity measures a material’s void content. Sand’s porosity impacts how well it holds and transfers air and water. In agricultural applications, high-porosity sand enhances soil aeration and drainage.
8. Thermal Conductivity
Sand is useful in applications that need insulation because of its moderate thermal conductivity. Because of its capacity to store and transfer heat, sand can also be used in concrete to provide thermal mass for buildings.
Uses of Sand in Construction
The properties of sand play a vital role as it is used in different construction processes.
- Concrete: When cement, water and aggregate are combined to make concrete, the properties of sand in the mixture provide a homogeneous mixture that reduces voids.
- Mortar: Again, the mixture of cement, sand and water bond masonry units together by creating a smooth, workable and easily applicable mixture.
- Plaster: To finish interiors and exterior walls and is sometimes added to plaster. Sand provides additional strength to the plaster because of the chemical properties of sand.
- Masonry: Sand used in masonry provides strength and stability. It is placed between the blocks during the brickwork to help level them and create a surface on which the mortar will stick.
Conclusion
Sand is a versatile material with a wide range of applications in the construction industry. It is essential to understand the bulk density of sand, the chemical composition of sand, and the physical properties of the sand to use it appropriately for certain tasks. The type of sand used has a big impact on the quality, durability, strength and stability of building components. Whether sand is used to create moulds for metal casting, produce concrete, or build structures, it is vital to study the properties of sand. At Brick & Bolt, you can get a professional team for construction-related knowledge and projects, and you can rely on the team of specialists for your next construction project to bring your dream project to reality.