Lightweight concrete has been used in the construction industry for ages and continues to be popular for a variety of reasons. Latest developments in lightweight concrete have added to its popularity as it reduces dead load, and improves sound reduction combined with several other benefits. This is why you will most often come across lightweight concrete for the construction of flyovers, bridges, and other major projects. However, lightweight concrete comes in different varieties based on the aggregates used to form concrete so check your requirements before ordering concrete mix delivery. We will discuss lightweight concrete in detail to help you make an informed decision.
Understanding Lightweight Concrete
Before we go into the details, it is vital to understand the concept of lightweight concrete. It is a lightweight mixture made using lightweight coarse aggregates such as slate, clay, or shale. These aggregates help the concrete develop low density.
When compared, structural lightweight concrete’s density is 90 to 115 lb/ft³ whereas regular-weight concrete’s density is 140 to 150 lb/ft³. Such characteristics tend to make lightweight concrete a preferable item for building modern structures with foundations that require minimal cross-sections.
That said, lightweight concrete has surely risen in popularity especially when compared to its counterparts. Plus, builders and contractors can also achieve a high compressive strength between 7,000 to 10,000 PSI but this is only possible with the addition of more water reducing pozzolans and mixtures that might compromise the density of the concrete.
How Does Lightweight Concrete Differ?
As mentioned earlier, lightweight concrete differs based on the admixtures used. The amount or the type of admixtures used affects both the finished weight and will also determine the products or process for successful installation. So, here are the types of lightweight concrete.
Low-Density Natural Aggregate Concrete
The first type of lightweight concrete is the low-density natural aggregate concrete. This type of concrete is normally produced from volcanoes and contains scoria, pumice, tuff, and cinder. Lightweight concrete also uses diatomite as an aggregate component.
The biggest advantage of using these aggregates is that they do not require much screening or crushing. The most common aggregate is Pumice, which is a glass formed due to frothy volcanic eruptions quickly cooling and turning into rock.
But, sometimes, pumice needs to be treated to increase its structural strength if it’s not as strong as expected in its original form. Meanwhile, other aggregates such as vermiculite or perlite are also used but not that much as they expand and quickly heat the material.
Processed Or Synthetic Aggregate Concrete
Processed or synthetic aggregate concrete as the term suggests is concrete that uses processed or synthetic aggregates. For instance, prepared clay or shay materials are heated, which helps expand the materials as the gasses within the materials and aggregates expand.
In addition to that, this concrete also uses materials with higher fusion points to prevent the material from sticking together while storing or mixing. Processed or synthetic aggregate concrete also uses expanded slag, which is treated with water or steam to act as an aggregate for lightweight concrete.
Finally, synthetic aggregates come in a variety of different types. These aggregates are constantly tested and approved to ensure they do not impact the strength and quality of the concrete. For example, oil sands or fly ash to recycled plastics are all used to form aggregates.
Cellular or Aerated Concrete
Cellular or aerated concrete is not only a result of the aggregate or product but also the process. This type of lightweight concrete is produced by introducing tiny air pockets in the concrete mixture. It is done via a chemical reaction that includes aluminum powder or hydrogen peroxide to produce gas within the concrete.
While the concrete is being poured, the chemical reactions result in the expansion of the concrete, which is then treated with high-pressure steam to cure and set the micro air pockets. Meanwhile, the other method uses pre-mixed foam that is stirred into the slurry to create tiny air voids in the concrete.
High-Performance Concrete
High-performance concrete is a specific type that is used for severe or specialized environments. This type of concrete is enhanced to cater to longer placement time requirements or specific density properties. For the finished concrete, it is not only the low-density aggregates that are used but also admixtures.
This gives the concrete the desired qualities required by the client. One thing you need to keep in mind when it comes to lightweight concrete is that it is a huge umbrella under which a variety lies based on the combinations of admixtures, aggregates, end-products, and processes.
These combinations and types of lightweight concrete differ based on the needs, preferences, and requirements of both the contractor and the task. You can ask the concrete delivery Montgomery County supplier to provide the exact type your project requires.
Where Is Lightweight Concrete The Same?
While we have discussed the different varieties of lightweight concrete, we should also shift our attention toward the factors that make lightweight concrete the same. The fact is that all types of lightweight concrete require accurate moisture testing during the drying stages if moisture has seeped through.
Additionally, several factors influence the drying schedule of the lightweight concrete slab, it is only the accurate moisture testing that can ensure the concrete is perfect for installation. Some tests such as plastic sheet tests, calcium chloride, or hood testing are proven to be highly inefficient.
However, tests like RH testing provide an accurate answer about internal moisture conditions by placing a sensor at 40% of the slab’s depth. Since moisture does not equally distribute throughout the slab during the drying process, it will only do so when the slab is sealed, which allows engineers to perform RH tests and confirm the presence of moisture.
Where Is Lightweight Concrete Used?
The Bank Of America Building
When it comes to discussing the applications of lightweight concrete, you cannot ignore the Bank of America building. This means the concrete can be used to build formidable structures especially since it can reduce the possibility of dead load being transferred from one floor to another.
Building New Structures On Top Of Old
Moreover, lightweight concrete is also used to build new structures on top of the old ones as it reduces the risk of collapsing. As mentioned earlier, lightweight concrete also helps reduce the project’s density, which makes it a good option for building bridges, decks, girders, etc.
Insulation
On the other hand, reducing the density also helps reduce the costs. Today, lightweight concrete due to its higher heat resistance and low thermal conductivity is also used to insulate walls, rooftops, water pipes, etc. It forms a protective layer to prevent steel corrosion helping protect and insulate steel against rotting.
Conclusion
If you’re new to this, lightweight concrete is something that needs to be understood before opting for application because even though it’s as durable as other concrete types, it’s not suggested for every type of construction. However, as it combines a lot of admixtures and aggregates etc. it can be used for a variety of projects with informed decision making. Contact a ready mix concrete supplier Rockville and share your requirements for the type of concrete you need.