Lean Concrete: Functions, Manufacturing Steps & Advantages

Lean concrete, also known as concrete rebate, is a concrete mixture with a lower cement content than regular concrete. Although it is referred to as low-quality concrete, lean concrete plays an important role in construction, especially as a base layer that supports the main structure.

Commonly used in road projects, runways, and building foundations, this type of concrete helps stabilize surfaces, prevent moisture, and keep work areas clean. Curious about its other functions? Let's take a look at the full discussion below!

What Is Lean Concrete?

Lean concrete is a concrete mixture with a lower proportion of cement and water than regular concrete, sometimes without fine aggregates. Due to this composition, lean concrete is often referred to as thin concrete or concrete rebate, and is categorized as low-quality concrete.

Lean concrete is generally used as a base layer in road construction, airport runways, or other projects, with a thickness of about 10 cm. Its primary function is to compact the soil and provide sufficient support for the structure above it, without requiring high strength, like normal concrete.

Although its mixture is similar to regular concrete, lean concrete is not considered a structural layer because it does not use reinforcement. The proportions of its materials are adjusted to be economical while still providing enough support.

The Function of Lean Concrete in Road Construction

Lean concrete is often used in road construction because it plays an important role in providing a stable foundation. Here are some of its main functions that support the quality and durability of road construction.

1. Helps Distribute Load

Lean concrete makes the road surface flat so that vehicle loads can be distributed evenly. This function prevents deep tire tracks and reduces changes in the shape of the road surface.

2. Supports Road Stability

Lean concrete also serves to provide sufficient density so that the asphalt or concrete layer above it is well supported. This can make roads more durable and reduce the need for repairs.

3. Controlling Soil Movement

Lean concrete helps reduce soil movement underneath caused by changes in temperature and humidity. This condition is important to prevent cracks on the road surface that can damage the road structure itself.

4. Forming a Solid Layer on Top of the Soil

Lean concrete serves to create a solid layer on top of the subgrade. This layer will later receive a thicker layer of asphalt or concrete. The goal is to distribute the weight of vehicle traffic more evenly to the subgrade while preventing the subgrade from deforming due to repetitive loads.

Steps for Making Lean Concrete

Before being used as a road base layer, lean concrete must undergo a structured process. Here are the steps for making it:

Site preparation: Clear the area to be cast from rocks, soil, or plants so that the surface is ready to receive lean concrete.
Determining the composition: Determine the proportion of materials according to project requirements and field conditions so that the concrete mixture meets standards.
Material delivery: Coarse aggregate, sand, and cement are delivered to the site according to the predetermined measurements.
Mixing of materials: Mix all materials in a mixer or similar equipment until a balanced concrete mixture is achieved.
Addition of water: Add water little by little until the right consistency is achieved, without reducing the strength of the mixture.
Lean concrete casting: Pour the mixture into the prepared area using heavy equipment as required by the project.
Compaction: Compact the concrete using special equipment to remove air pockets so that the mixture is denser and stronger.
Curing or water spraying: Maintain the moisture of the concrete surface by spraying water regularly so that the hardening process runs optimally.
Maintenance: After hardening, perform routine maintenance such as minor repairs or patching if cracks appear.
Follow-up work: Once sufficiently strong, the main concrete or asphalt layer can be applied over the lean concrete according to the road design.

The Advantages of Using Lean Concrete

Lean concrete is often chosen in construction projects because it has several advantages that support work efficiency. Here are some of its main benefits:

More cost-effective: Because the mixture is simpler, the cost of producing lean concrete is lower than regular concrete.
Fast producing process: Lean concrete tends to be faster to produce because it does not require additional materials or complicated processes.
Sufficient strength: Despite its minimalist composition, lean concrete is still capable of supporting structural loads as required by the project.
Good stability: This material can serve as a stable foundation for the construction above it, while also helping to reduce the risk of cracking or shifting.
Adjustable quality: Its composition is flexible, so that the quality of the concrete can be adjusted according to technical requirements and available budget.
More practical installation: Installation can be done with simple tools without having to go through a manufacturing process, such as paving blocks.
Low water absorption: Lean concrete does not have gaps like the interlocking joints in paving blocks, so water does not easily seep in and damage the structure.

How Important Is Lean Concrete in a Project?

Lean concrete is not always needed in all construction projects. Its function is to help workers make good-quality concrete castings. This concrete slab can be made directly on the excavated ground surface, then filled with a layer of fill, foundation, and reinforced concrete ground beams.

The installation of steel reinforcement for new foundations and slabs can begin once the concrete has dried and hardened completely. This allows workers to complete the reinforcement more easily, as they are not bothered by wet soil.

That is the complete explanation of lean concrete, from its function and manufacturing process to its advantages in the construction industry. As an important part of the basic structure, lean concrete requires high-quality main materials so that the construction results are stronger, more stable, and more durable.

For those of you who are working on construction projects, especially in the road construction sector, such as highways, parking areas, runways, and toll roads, choosing high-quality concrete is crucial.

To address the challenges of time efficiency, cost, and quality control on-site, Semen Merah Putih offers construction solutions through its premium products. One of them is Semen Merah Putih ULTRAMIX-G, a Portland cement designed for ready-mix and precast concrete, offering optimal strength and easier installation.

For projects requiring resistance to sulfate attack and low hydration heat, Semen Merah Putih PRIMAPLUS is available, which also supports environmental sustainability. If you need high flexibility for various construction applications, Semen Merah Putih FLEXIPLUS is the ideal choice, available in three types: GU, MS, and HE, to suit your project requirements.

Meanwhile, Semen Merah Putih SUPERMIX, as a Portland Composite Cement, is designed for concrete with optimal density and compressive strength, as well as ease of casting that supports the quality of fresh concrete.

With these innovations, Semen Merah Putih offers a complete solution for faster, more economical, and higher-quality road construction.

Working on a construction project? Choose high-quality cement for the best results! Trust Semen Merah Putih for your road construction solutions and find the product that suits your project's needs. Contact us now for more information!