Concrete Masonry Units also known as CMU are blocks used in the construction industry to form a concrete block structure like a wall or a fence. These are generally made up of concrete and aggregates of certain design mixtures depending on strength required but systems used as masonry units are non-load bearing in nature or do not and should not be allowed to carry any vertical loads at all.
Now, if you want to build a concrete block or concrete masonry unit you need to have an Understanding About Checklist to compliance to the approved project documents such as blockwork shop drawing, method statement for blockwork, and inspection and test plan.
So, if you want to know more about concrete block or concrete masonry units here are the most common type of concrete blocks used in the construction industry.
1. Hollow concrete blocks
Commonly used in the construction industry, concrete hollow blocks are usually manufactured using lightweight aggregates with a certain design load depending on the nature of the member it will be used into. Normally, concrete hollow blocks have voids of ¼ its gross area and the solid area should be not less than half of its area to attain its maximum allowable load capacity, study suggests. The voids are generally filled with mortar of lightweight aggregate material as well.
There are two kinds of concrete hollow blocks; load-bearing concrete hollow blocks and non-load bearing concrete hollow blocks. It is available in sizes such as 100x200x400mm, 200x200x400mm, 150x200x400mm and so on.
2. Aerated Autoclaved Concrete Block (AAC)
Most of the time compared with bricks but is different in a lot of ways. Aerated Autoclaved concrete blocks are lighter and bigger version of bricks. Mostly made with same ingredients as of bricks but with a different composition which made the material a vessel for cost-cutting. Studies show that using autoclaved aerated block has diligently reduced the overall steel and concrete consumption by 15% and 10%. Apparently, in the cost-benefit factor part, autoclaved aerated block past by bricks in several areas such as construction time, adaptation to various surfaces, fire resistance, and cost.
For the installation of AAC block, a method statement must be submitted for approval before work commences.
3. Concrete Bricks
Concrete bricks typically are small rectangular block arrange and piled systematically to create a rigid wall. These bricks are usually made up of cooked clay or concrete. Some manufacturers use solid concrete while others play with its cement and aggregates ratio for economic purposes. Other manufacturers also created bricks with different color as per request of some clients. Concrete bricks are usually used in fences, facades, as it provides the good aesthetic and slick look.
4. Solid concrete blocks
Way denser and bigger than concrete bricks, solid concrete blocks are manufactured to be strong, heavy, and created out of naturally dense aggregates. These solid concrete blocks are strong enough that it is used for large masonry units that are load-bearing in nature. Solid concrete blocks are just similar to concrete brick but are way costlier and heavier and can withstand more forces as compared to bricks.
5. Lintel blocks
These concrete blocks are used in preparation for lintel beams. These lintel blocks are manufactured in such a way that it serves as a masonry unit and a formwork itself. Aesthetically, lintel blocks have a deep groove where reinforcing bars are put along with the concrete. Meaning, they serve as permanent formwork systems for the lintel beam member. This is found to be efficient and useful by most builders as they served two different purposes. A two in one product it is.
6. Paving Blocks
Paving blocks are generally just a rectangular or square box made up of reinforced concrete. As these blocks are used in paving and road shoulders, these have to be painted with high-visibility concrete paints so motorists and drivers could see it right away. Also, these blocks have to be rigid and firm enough to receive any car collisions.
Pavings blocks are also used in parks, walkways, and sometimes in parking areas. The common size of paving block is 60mm.
7. Concrete stretcher block
Again, somewhat similar to corner block, concrete stretcher blocks are used to combine masonry units. With respect to its looks, concrete stretcher block is relatively the same with common hollow block but their faces are laid parallel with respect to the face of the wall.
Alongside every masonry units stated above, these concrete blocks come with reinforcing bars and approved mortar and paste or adhesive material. Furthermore, choosing a masonry unit is solely dependent on the needs of the builder, a combination of this masonry unit is advisable.
Each and every masonry unit is created and manufactured for each and different purposes. It is advisable to ask the supplier as they are the ones knowledgeable about their products. They can give ideas and impart knowledge that is not common. Engineers may also ask these suppliers to have a demo on how to install their products.