What is Blockwork Construction?

Blockwork is a type of masonry construction technique using large concrete or cement blocks. The blocks used here are larger than normal brick and are mostly hollow to make them lighter and easier to work with. 

Blockworks have been in use since the 1930s, from ordinary cement. Now it is made from stone aggregates, and industrial waste also called breeze brick making it more efficient, sustainable, and eco-friendly.

Blockwork is used for the construction of load-bearing walls, retaining walls, partition walls, and even foundation structures.

This article explores the various features and types of blockwork construction in detail.

Features of Blockwork Construction

Blockwork construction offers a number of high-standard performance features compared to other masonry construction. Some of the benefits include:

1. Durable Low-Maintenance Construction

Concrete blocks in blockwork construction offer a durable solution with minimal upkeep, making them an excellent choice for projects where low-maintenance requirements and heightened security are priorities.

2. Impact Resilience and Water Integrity

Blockwork construction benefits from concrete's inherent resilience to impact, providing robustness for both internal and external walls. Concrete blocks maintain their structural integrity even in the face of water exposure, contributing to the overall stability of the construction.

3. Inherent Fire Resistance for Safety and Property Protection

Concrete block walls in blockwork construction showcase inherent fire resistance, surpassing building regulations and ensuring effective fire isolation. This feature not only prioritizes the safety of occupants but also enhances property protection in the event of a fire.

4. Urban Construction Advantages

In urban blockwork construction, the inherent fire resistance of concrete blocks becomes a significant advantage, aligning with recent Health and Safety Executive (HSE) guidance and potentially eliminating the need for costly additional fire prevention measures.

5. Thermal Efficiency for Energy Conservation

Concrete blocks in blockwork construction exhibit excellent thermal insulation properties, particularly in lighter-weight variants. 

Denser aggregate blocks, though heavier and less thermally insulating, offer higher thermal mass, contributing to effective heating and cooling strategies within buildings.

6. Airtightness for Enhanced Energy Performance

Achieving effective and durable airtightness is a key feature of blockwork construction with concrete blocks. Whether through plaster or render coat finish, perimeter-sealed drylining, or a combination of both, these options ensure that blockwork constructions meet high standards of energy efficiency.

7. Acoustic Insulation for Noise Reduction

Blockwork construction benefits from the inherent mass, stiffness, and damping properties of concrete blocks, making them an ideal choice for reducing noise levels between buildings and within them. 

Specially designed masonry products cater to blockwork applications, ensuring enhanced acoustic insulation in settings like schools and medical facilities.

8. Adaptability 

Blockwork construction is mostly assembled at the site providing flexibility and design adaptability. A blockwork structure has structural support inherent within it thus providing flexibility on site while working with internal fixtures and fittings.

9. Material Efficiency and Cost Effectiveness

A single blockwork wall is a combination of various performance benefits as mentioned above making it materially efficient and cost-effective.

Concrete Blocks Used in Blockwork

The type of block selected for blockwork construction is dependent on the:

• Density of the block
• Load-bearing characteristics
• Appearance of the block
• Weight and handling properties
• Thermal characteristics of the block

Types of Concrete Blocks

The fundamental classification of concrete blocks is Hollow and Solid Concrete Blocks.

Solid Concrete Blocks

Solid concrete blocks commonly called concrete masonry units are solid manufactured with dense aggregate. As they are not hollow, they are used for applications demanding high durability and stability like walls, foundations, firepits, steps, and planters. 

There are very less varieties of solid concrete blocks some of them are:

1. Aerated autoclaved block (AAC)
2. Cellular lightweight block
3. Expanded clay aggregate block
4. Fly ash block
5. Paving Block

Hollow Concrete Blocks

Hollow concrete blocks are masonry units with holes in one-quarter to one-half of the total area, with the hollow parts either together or split into components. Hollow blocks come out to be lightweight and allow the placement of wires and pipes through the building structures. 

Reinforced concrete block walls enhance stability and strength. They are ideal for boundary fences and large structures.

The nine varieties of hollow bricks are:

1. Bullnose block
2. Column block
3. Corner block
4. Jamb block
5. Lintel Block
6. Partition Block
7. Pillar Block
8. Splitface block
9. Stretcher block

How to Construct a Concrete Block Wall: Essential Elements

When constructing concrete block walls, the fundamental building elements are generally consistent across various wall types. The application of these elements, however, may vary based on factors such as the wall's shape, size, and designated usage.

1. Foundation of the Building: Concrete block walls require placement on a sturdy concrete ground, regardless of their intended purpose. The depth and size of the foundation can vary depending on the wall's dimensions and the load it will bear. Typically, the foundation extends approximately twice the width of the wall and about one foot below the surface.
2. Concrete Blocks: The selection of block shape and size should align with the intended function of the wall.
3. Mortar Joints: Each block is connected to another through mortar, a crucial process for enhancing the overall strength of the concrete structure.
4. Reinforcements: To prevent cracking or damage from external factors, concrete block walls are reinforced both vertically and horizontally. Vertical reinforcements are placed at specific intervals within the block spaces during the drying phase, while horizontal reinforcements are added after every third or fourth row of blocks.

Construction Details of a Concrete Block Wall

1. Draft Creation: Establishing the foundation draft involves using piles and wall wires.
2. Digging: Depending on the foundation's size and external conditions, excavation is performed. A solid foundation is vital for the overall strength of the structure.
3. Groundbreaking: Concrete is poured into the excavated area, often covered at the top with timber. Before commencing wall construction, it is essential to ensure the foundation is completely dry.
4. Block Arrangement: Once the foundation has fully hardened, an outline is drawn for block placement. Applying a 2.5 cm mortar along the outlined borders, the blocks are then positioned and gently tapped to ensure a secure fit in the mortar.
5. Adding Reinforcements: Strengthen the wall with both horizontal and vertical metal reinforcements.