What is lightweight concrete?

Introduction

The lightweight concrete is one of the most widely used building materials and concrete products. By the growing population and the need for more construction, building strength has also been paid attention to by contractors and builders to construct a high-strength building in considering current standards.

Besides saving time and energy when construction, this product leads to an increase in the building’s strength against accidents such as earthquakes, floods, etc., and reduces your probable further expenses. This article is aimed to make you more familiar with a product helping you in this field.

The characteristics of light-weight concrete

This product contains porous aggregates which are used for building strength. This concrete is similar to conventional concrete however its weight and density have significantly been reduced and its strength has been multiplied.

Using this product is an important parameter in construction. The structure of this product is in a way that it has a lower weight than conventional and heavy-weight concrete and it also has more advantages than conventional concrete. The use of this concrete in construction leads to a reduction in the building weight.

On the other hand, the weight of conventional concrete is 2400 Kg but the weight of lightweight concrete is 1000 Kg per cubic meter. It is simply understood that this concrete has a lower weight.

Different types of light-weight concrete

The process of producing this product is accomplished via the following methods:

• Replacing the light-weight aggregates instead of ordinary aggregates
• Developing gas and foam inside the concrete
• Developing porosity

Different types of this concrete are categorized based on the aforementioned items. Moreover, the weight withstood by the concrete depends on these items. In case of the need for reducing the permeability, the air-entraining agent is used. Also, different types of them based on the production process include gas or air entraining concrete and concretes without fine aggregate which is described in the following.

1. Lightweight concrete

The properties and ability of the lightweight concrete can be determined based on its aggregate. Using lightweight concrete in building construction significantly reduces weight as well as reducing the current expenses in construction.

Autoclaved aerated concrete

This concrete is also known as aerated concrete, foam concrete, and cell concrete. Artificial materials and natural materials with lower weights are not used in this type of concrete to reduce the weight and increase the strength, respectively. Since ways to produce this type of concrete are divided into sponge, foam, and autoclaved concrete.

In the foam or sponge concrete production method, bubbles are developed inside the concrete by adding air entraining chemicals. This leads to a reduction in the weight of the concrete. The other method is to inject bubbles before producing the concrete.

The CapcoAir SLA is used to improve and develop the bubbles in the concrete. The price of this product varies depending on the type of the product ad its quality level. For this reason, the Hamgerayan Production Company (Capco) is very active and provides high-quality products to customers.

This type of concrete is suitable for grading and thermal insulation, flooring, walling, and suitable floor covering. This type is also very efficient for the sewage system.

Concrete without fine aggregate

This concrete is produced by destroying fine aggregates and using coarse aggregates in combination with water, cement, and coarse material.

In case of the need for reducing the water-to-cement ratio, the concrete superplasticizer CapcoNorm SPC218 concrete admixture can be used. The price of the aforementioned admixture varies in terms of market fluctuations. Therefore it is better to purchase this product from authentic representatives.

Separating the fine aggregates from the mixture of this concrete leads to a significant increase in porosity and a reduction in strength. That is where insulation arises. These materials are used for surface insulation because they are not able to withstand the load.

Therefore, concrete without fine aggregate is not used in reinforced concrete and its most uses will be in bearing walls.

Different types of light-weight concrete based on density

These products are divided into the categories below, all of which have been introduced in the following:

1. Concrete with low density

This product is used for insulation. The low weight of this concrete barely reaches 800 Kg/m³ and mostly will be used as thermal insulation. Its compressive strength will be between 0.69 and 6.89 N/mm² which is a low value.

۲ . Concrete with an average density

This type of concrete with good strength is placed in low-density and structural concrete and used to reduce building weight in building construction.

۳. Structural concrete

Structural concrete is used in bearing parts of the building due to its high weight. The thermal insulation of this product is more than conventional concrete and will not be used for insulation.

The advantages of lightweight concrete in building construction

This product has many advantages and is one of the most desired items for engineers. The advantages include:

• Reducing building weight
• Increasing building durability
• Increasing strength of the structure due to its lighter weight
• Easier transportation and less current expense
• Thermal and acoustic insulation
• Reducing construction time
• Maintaining moisture within a long time and not cracking due to increasing and reducing the temperature
• Resistant to natural disasters such as earthquakes, floods, and wind
• The possibility of using it in pre-cast structures

The use of lightweight concrete

This concrete is widely used in different places. The most important use of this product is in residential and non-residential building construction in seismic regions. Other uses of the product have been briefly highlighted in the following. 

• Underground shelter
• Using for beam, foundation, roof, and bearing walls
• Using for steel decks and inclined walls
• Using for coating and composite plates
• Using for partition wall panels, pre-cast buildings, and wall blocks
• Building insulation due to high porosity

The difference between ordinary and lightweight concrete

One of the most important differences between ordinary and lightweight concrete is density because lower density leads to a reduction in the dead load of the structure. Also, the ruptures of lightweight concrete occur in the middle of the concrete. Vice versa, the ruptures of the ordinary concrete occur around it. The other item will be the strains from creep or shrinkage in these two types of concrete. Due to the high porosity in this type of concrete, a lower elasticity modulus will be developed than in ordinary concrete.

Conclusion

One of the most important uses of lightweight concrete is in the seismic regions and it has been popular regarding the performance of this product. By using this product you can have stronger, lighter, and safer structures.

One of the Companies providing this product is Hamgerayan Production Company (Capco) which started its activity in 1382. This company provides and sends services and products such as heavy and lightweight concrete. Therefore, you can contact 02189331 to order your building products and visit www.capco.co.ir/en for more information.