The selection of wall materials is a critical aspect of building construction, influencing a structure’s durability, insulation, load-bearing capacity, and aesthetics. In this article, we will explore various wall materials, focusing on their composition, properties, and practical applications in construction.
Wall Materials
1. Fired Bricks
Fired bricks are a classic building material, made by sintering clay. Their compressive strength ranges from 10 to 30 MPa, with an apparent density between 1500 and 1800 kg/m³. These bricks have a thermal conductivity of 0.78 W/(m·K), making them suitable for heat management in various climates. Additionally, their frost resistance (15 cycles) makes them reliable in colder regions. Commonly used in walls, bases, columns, and brick arches, fired bricks offer versatility and strength.
2. Fired Porous Bricks
Fired porous bricks are also made from sintered clay but differ from standard fired bricks due to their lightweight, porous structure. With compressive strengths ranging from 7.5 to 30 MPa and an apparent density of 1100-1300 kg/m³, they are primarily used for insulating load-bearing walls. These bricks provide excellent insulation while maintaining structural integrity, making them an ideal choice for energy-efficient buildings.
3. Fired Hollow Bricks and Blocks
Fired hollow bricks, known for their low weight and thermal insulation properties, have compressive strengths between 2.0 and 5.0 MPa, with a density of 800 to 1100 kg/m³. These bricks are excellent for non-load-bearing walls and insulating walls. Their lower weight reduces the structural load, making them cost-effective for multi-story buildings.
4. Lime-sand Bricks
Lime-sand bricks are produced through autoclaving fine silicate sand, lime, and water. With a compressive strength of 10-25 MPa and a thermal conductivity of 0.6 W/(m·K), they are suitable for many applications similar to fired bricks. However, these bricks are limited in environments with prolonged exposure to flowing water or high temperatures exceeding 200°C. Despite this, their uniform appearance and color options make them popular for aesthetic architectural projects.
5. Autoclaved Fly Ash Bricks
These bricks are composed of fly ash, lime, aggregates, and gypsum. With compressive strengths ranging from 7.5 to 20 MPa, they provide a sustainable alternative by repurposing industrial waste materials like fly ash. Their density of 1500 kg/m³ and resistance to shrinkage make them a reliable option for general construction, offering the same applications as lime-sand bricks.
6. Aerated Concrete Blocks
Aerated concrete blocks are manufactured using porous concrete, lime, and aluminum powder, resulting in a highly insulative material with compressive strengths of 2.2-3.0 MPa for the 500 grade and 4.2-5.0 MPa for the 700 grade. With excellent thermal conductivity (0.10-0.16 W/(m·K)) and frost resistance, these blocks are often used in building walls and for insulation purposes, particularly in regions requiring energy-efficient thermal management.
7. Aerated Concrete Boards
Similar to aerated concrete blocks but reinforced with steel bars, aerated concrete boards offer similar strengths and thermal properties. These boards are widely used for outer walls and partition walls in both commercial and residential buildings, providing both strength and insulation.
8. Foam Concrete Blocks
Foam concrete blocks are created using cement, foam agents, and water, forming a lightweight but robust material. With a compressive strength of 2-3 MPa and thermal conductivity of 0.12 W/(m·K), they are used in similar applications as aerated concrete blocks, particularly for insulation purposes in walls of low-rise buildings.
9. Common Small-Sized Concrete Hollow Blocks
These blocks are produced by mixing cement, sand, stone, and water. They feature compressive strengths ranging from 3.5 to 15 MPa and are used in load-bearing walls of low- to mid-rise buildings. Their high density (1300-1700 kg/m³) and reasonable thermal conductivity (0.26 W/(m·K)) make them ideal for robust, cost-effective construction.
10. Small-sized Lightweight Aggregate Concrete Hollow Blocks
Made with lightweight aggregates, these blocks are lighter than standard hollow blocks. With compressive strengths between 2.5 and 10 MPa and a density ranging from 500 to 1400 kg/m³, they are suitable for both insulating and non-load-bearing walls. Higher strength blocks can also be used for load-bearing applications in multi-story construction.
11. Lightweight Concrete Wall Boards
Lightweight concrete wall boards are reinforced with steel bars and made from a mix of cement, sand, and lightweight aggregates. These boards, with compressive strengths between 10 and 20 MPa and a thermal conductivity of 0.35-0.5 W/(m·K), are versatile, serving in both non-load-bearing and load-bearing walls, depending on their strength.
12. Lightweight Sandwich Boards
Lightweight sandwich boards are made from polystyrene cores, reinforced with steel mesh and cement mortar. With heat resistance and a soundproof index of 40 dB, these boards are commonly used in self-supporting outer walls, partitions, ceilings, and roofs, providing thermal insulation and soundproofing.
13. Concrete Sandwich Boards
Concrete sandwich boards consist of reinforced concrete layers surrounding insulating materials like rock wool or foam concrete. These boards are used for load-bearing and non-load-bearing outer walls. The load-bearing variant has a density of 500-542 kg/m³ and a thermal conductivity of 1.01 W/(m²·K), making it a strong and insulating choice for exterior walls.
14. Gypsum-based Boards (Paper, Fiber, Decorative)
Gypsum-based boards, including paper and fiber variants, are lightweight materials used primarily in interior partitions. With an apparent density of 600-1000 kg/m³ and a bending load of 400-850 N, these boards offer thermal insulation and soundproofing capabilities. However, they are best suited for dry environments due to their poor water resistance.
15. Glass Fiber Reinforced Cement Boards (GRC)
GRC boards are composed of low-alkali cement, anti-alkali glass fiber, and lightweight aggregates. With excellent bending strength (>25 kJ/m²) and thermal conductivity (≤0.2 W/(m·K)), these boards are widely used in inner partition walls and as protective exterior cladding.
16. Natural Stone
Natural stone, although porous and prone to thermal shock, is used in random rubble walls. Its natural aesthetic appeal and durability make it a favored material for outdoor walls and landscaping.
17. Solid Concrete Blocks
Solid concrete blocks are manufactured from cement, sand, and aggregates, offering high structural capacity and fire resistance. These blocks are commonly used in load-bearing walls due to their strength and ease of use in construction.
18. Dressed Stone (Ashlar Masonry)
Dressed stone, cut into smooth cuboids, is a high-strength material (crushing strength > 100 N/mm²) that is fire-resistant and aesthetically pleasing. These stones are typically used in ashlar masonry walls, where precision and durability are key.
19. Glass Blocks
Glass blocks are made from silica sand, soda ash, and limestone. With a heat transmission ratio of 2.97 W/(m²·K), a soundproof index of -42 dB, and up to 80% light transmittance, glass blocks are widely used for insulation, cladding, and even structural components in modern architecture.
Conclusion
From traditional fired bricks to modern composite boards, the wide variety of wall materials available today allows for tailored construction solutions. Each material offers a distinct set of properties, making it important to select the right material for your specific building requirements, whether you need strength, insulation, aesthetics, or cost-efficiency.