Whether you’re planning to initiate a construction project, renovate your home, or prepare for an event, you’ll probably need concrete blocks at some point during the project. Concrete blocks are a form of construction material composed of concrete, cement, sand, water, and other additives. They are used in different types of construction applications.
There is a common misconception that concrete blocks are mainly useful for controlling traffic in the form of large concrete barriers. While they function tremendously in that application, concrete blocks perform well in numerous residential, public, and industrial applications as well.
As a highly adaptable and versatile material, concrete has been used by architects and engineers to construct sturdy, long-lasting buildings. Its most significant properties include resistance to fire, a variety of aesthetic qualities, high structural capacity, strength, longevity, resistance to water, and insulating and acoustical advantages. For many applications, they serve as minimum maintenance, yet economical building materials, while meeting the specialized requirements of the client.
Table of Contents
- Uses of Concrete Blocks
- Properties of Concrete Blocks
- Types of Concrete Blocks
- Concrete Bricks
- Solid Concrete Blocks
- Aerated Autoclaved Concrete Blocks
- Hollow Concrete Blocks
- Lintel Blocks
- Concrete Stretcher Blocks
- Jamb Concrete Blocks
- Concrete Pillar Blocks
- Concrete Corner Blocks
- Partition Concrete Blocks
- Bullnose Concrete Blocks
- Paving Blocks
- Expanded Clay Aggregate Solid Construction Blocks
Concrete blocks have a wide range of uses. They are commonly used as retaining walls in both residential and commercial contexts. They also serve as security barriers, lined up on roads to control the flow of foot traffic at any given event. Event management companies often use them to organize special entrances and exits. Concrete blocks are an incredible source of vehicular traffic control, too. Large blocks can be lined up side by side to organize traffic.
Concrete blocks are designed in a variety of ways to make them adaptable to different applications and contexts. Learning about their different types and their uses is important so that you select the right one for your project to ensure longevity and stability of the structure. But before we jump into the different types, let’s look into their properties:
Properties of Concrete Blocks
Concrete blocks are in demand due to their compressive strength that’s common in all the types. There are numerous methods in place to estimate the concrete’s strength as well as to ensure whether the manufactured concrete meets the standard strength requirements. To produce a significantly stronger concrete block, solid grouting into the cells can be done, which involves inserting steel rods called rebar into openings in the blocks.
A drawback of concrete blocks is that it absorbs water. Thus, to produce a more waterproof concrete block, a mixture of coarse and fine particle material should be used during manufacturing. What determines the degree of permeability of a concrete block is the amount of cement used in production. The higher the cement content in the mixture, the lesser the permeability.
In addition, applying the various washes available or using waterproof compounds after erecting the blocks also helps to keep the water out.
Besides this, the fire resistance of concrete blocks depends on the type of unit and the coverage area. To obtain in-depth information on the fire resistance properties of various types of concrete blocks, go through the document issued by the American Concrete Institute that includes their fireproof values.
As far as aesthetic properties are concerned, manufacturers now offer blocks in a multitude of textures, colors, and finishes, as demanded by architects and engineers. The ever-evolving construction industry continues to demand new concrete block shapes and sizes to cater to innovative building designs.
When it comes to the insulating properties, they vary with the density of the blocks as well as with the type of manufacturer. The insulating properties are recorded using thermal conductivity tests performed by the manufacturers. When manufacturers aim to produce blocks with high heat-insulating properties, they reduce the concrete block density by volume and generate low-weight blocks. Furthermore, the insulating properties of a concrete block wall can also be increased through solid grouting of the cells.
The acoustic properties of concrete blocks are determined by multiple aspects. The characteristics of the material used during manufacturing are an important factor in this regard. In addition, the junctions and connections between the blocks and construction type also play a crucial role. To obtain maximum acoustic control, the best approach is to follow the guidelines issued by the ACI on concrete blocks installation.
Types of Concrete Blocks
Concrete bricks are systematically piled blocks, rectangular in shape, primarily used to build rigid walls. Normally made of concrete or cooked clay, they are ideal for building fences, giving them a slick and aesthetic look. While some manufacturers use cement and aggregates to make these blocks, others stick to solid concrete. Based on the requirements of clients, other materials may also be used to get the concrete to take on certain colors.
Solid concrete blocks are among the most commonly used concrete blocks that are way bigger and denser than concrete bricks. They are designed to be heavy, strong, and are produced from naturally dense aggregates. Due to their strength, they are mostly used for building load-bearing walls and structures. Although they are similar to concrete bricks, it’s their weight and cost that distinguishes them from concrete bricks. Also, their larger size means that they lead to quicker construction of a structure as compared to bricks.
Source: Quality engineers guide
Often confused with concrete bricks, aerated autoclaved concrete blocks are composed of the same aggregates as bricks, but the composition or mixture varies, resulting in a larger yet lighter version. This quality has enabled a significant reduction in cost. Plus, research suggests that its high durability has led to a reduction in the overall consumption of steel by 15% and concrete by 10%. Aerated autoclaved blocks overshadow bricks not only in terms of cost but also in terms of construction time, fire resistance, and surface adaptability.
But this concrete block is more expensive than the traditional concrete and wood-frame construction. Plus, the strength of aerated autoclaved block is one-sixth to one-third that of a traditional concrete block.
Aerated autoclaved concrete blocks can be drilled and cut using traditional woodworking tools such as simple power drills and band saws, making them highly workable units. However, their low-density and lightweight nature mean that their compressive strength, bulk density, moisture content, and shrinkage must be assessed prior to its use.
Aerated autoclaved concrete blocks come in lengths of 24, 32 and 48 inches. Thickness varies from 4 to 16 inches, whereas height is typically 8 inches. As they are more versatile than standard concrete, they are used in the construction of walls, roofs, and floors. Besides being strong and fire-resistant, the blocks are excellent for sound and thermal insulation. However, to ensure maximum longevity, they must be coated with an applied finish such as a polymer-modified stucco, finished with a siding or covered with a natural or engineered stone.
AAC walls constructed in basements must be covered with thick waterproof material or membrane to prevent AAC blocks from getting damaged by water. In addition, exposure to weather or soil moisture will cause AAC surfaces to break down. Hence, further protective actions must be taken.
On the other hand, no coatings are necessary when AAC blocks are used in interior applications. They can be safely left exposed. Yet, people normally apply finishes such as plaster, paint, drywall, or tiles. Because of their lightweight, AAC blocks are not only easy to install and handle, but also recyclable and allow for easy cutting to create chases and holes for plumbing and electric lines. In contrast with solid concrete blocks, AAC blocks offer economical shipping and handling.
However, you may experience diminishing quality, and fading color of AAC blocks over time. When used externally, AAC blocks will break down soon unless a tough coating is applied. When installed in areas with high humidity, external finishes demand high vapor permeability while internal finishes demand low vapor permeability.
Source: The balance small business
Hollow Concrete Blocks
A hollow concrete block is defined as a concrete block containing a void area that’s 25% greater than the gross area, and the solid area should be greater than 50%. Since it is made from lightweight aggregates, the blocks are light, making them easy to install. Depending upon the application of the block, the hollow area may be manipulated, such as dividing it into components or making slight adjustments in the shape of the void area. Let’s have a look at its variations:
Lintel blocks, also known as channeled blocks, are U-shaped concrete masonry units. They are primarily used in the preparation of lintel beams. Attached on top of windows and doors, these blocks bear the load coming from the top. The deep groove present in lintel blocks is filled with concrete along with reinforcement bars once the blocks are placed.
Given their solid bottom, lintel blocks’ underside can be exposed at openings, which means they don’t allow vertical reinforcements to extend through them. Since wall systems typically have a combination of vertical and horizontal reinforcement, lintel blocks aren’t used in their construction. However, the bottom of the lintel beams can be removed to allow for the extension of the vertical reinforcement through it. In this way, lintel beams can be used to create bond beams in walls with vertical reinforcing, too.
Lintel blocks are more often used in bearing walls without vertical reinforcing below the ends of steel joints. Yet, a steel-bearing plate for the bar joints is normally placed in the grout.
Source: Concrete construction
Concrete stretcher blocks are commonly used as hollow concrete blocks. Their primary purpose is to join the corners of masonry units. While they look pretty similar to normal hollow blocks, their length faces are designed in a way that they are parallel to the face of the wall.
Jamb Concrete Blocks
Jamb blocks are used to deal with an elaborated window opening in a wall. Connected to a stretcher and corner blocks, they often help to provide space for the casing members of the window, particularly in the case of double-hung windows.
Unlike stretcher concrete blocks and corner blocks, concrete pillar blocks are designed in a way that both their ends are visible. This is why they are also known as double corner blocks. They are most commonly used in building pillars or piers.
Concrete corner blocks serve as the corner blocks in masonry or the ends of door openings or windows. One corner of the block is plain while the other is a stretcher design with the face parallel to the wall. The plain side is exposed to the outside while the other serves as a stretcher lock towards the inside.
Partition concrete blocks are the same as concrete pillar blocks except that these blocks have a larger height than their breadth. The hollow part is often divided into two to three components. These blocks are ideal for the construction of partition walls.
Bullnose Concrete Blocks
Bullnose concrete blocks are the same as concrete pillar blocks. The only minor difference is that they have rounded edges. Thus, if you prefer rounded edges, bullnose concrete blocks are the right option for you.
Source: The constructor
Paving blocks are square or rectangular shaped boxes made from reinforced concrete. Simply put, they are just a decorative technique for creating pavements. While mostly used in road construction, paving blocks are also useful in the construction of car parks and walkways. When used for building road shoulders and paving, they must be coated with high-visibility paints, so they are easily visible to drivers and motorists.
Expanded Clay Aggregate Solid Construction Blocks
This variant is created from lightweight, expanded clay aggregates with a dry density up to 750 kilograms per cubic meter. Masonry units known as Ecasolid Construction Blocks are made using expanded clay aggregates of class F fly ash and cement. As lightweight construction blocks, they help reduce the overall structural load by 40-50%.
These construction blocks are not only waterproof but also chemical and fire-resistant. These features help enhance their versatility, durability, and ease of use. Apart from offering excellent thermal and sound insulation, they are considered environmentally sustainable.
In addition, ECA construction blocks are relatively more economical than other concrete blocks and are considered a premium segment of solid green construction blocks. These easy-to-modify blocks can be nailed, carved, drilled, and shaped easily. This means that they can be easily cut to install conventional or concealed wiring and pipes. While they allow for easy installation using regular cement mortar, decorative paints are often applied or coated in the end.
As opposed to using traditional concrete blocks, the application of ECA construction blocks reduces the mortar expense by 70%, as well as saves on the reinforcement costs.
In conclusion, different types of concrete blocks are designed and manufactured for different purposes. They are extremely versatile construction materials that have various uses at events, homes, and for storage purposes. Yet, all come with approved mortar, reinforcing bars and paste material. Prior to the purchase, it is advised that you consult a few suppliers so that you end up getting the one that fits your purpose. Many manufacturers even provide a demo of how the blocks have to be installed.