Geocell Concrete Road Installation

In geotechnical road construction, many clients often ask a key question: after filling Geocells with concrete, do they need an extra concrete layer on the top? The subgrade condition, vehicle load and road use will decide the right installation method. Wrong construction will cause road settlement, cracks and short service life.

Recently, one client from Colombia asked about our 75mm geocell installation for a new internal road. They had questions about the gravel base and the concrete filling. We gave professional suggestions based on their actual site situation. Below is our full communication for your reference.

Hi Claire, how are you?

We are about to start installing the geocells in one of our projects here in Colombia. Today we visited the site with some engineers, and a question came up regarding the correct installation when using concrete as infill.

They mentioned that after installing the geocells and filling them with concrete, it might be necessary to add an additional concrete layer on top.

Could you please confirm if this is correct? Is it necessary or recommended to apply another concrete layer over the filled geocells, or should the system work properly just with the cells filled and leveled?

If you have any technical guidelines or recommendations for this type of application, it would be very helpful.

Thank you!

Regarding this question, I checked with our engineer.

You should choose the correct installation method based on the following points:
1, What’s your subgrade strength? Is your road an existing road with good subgrade strength? Or is the road newly built without any strength?

2, Will you add a layer of gravel under the Geocell to improve the subgrade strength? And what’s the thickness of the gravel?

3, What’s your vehicle type? Mainly for motor vehicles or bicycles? And what about the weight of the cars? And what is the traffic volume?

If your road is an existing road with good strength, or you have added a layer of gravel to improve the subgrade strength. At the same time, if not many vehicles pass by, you can just fill the 75mm Geocell with concrete and level it is ok.

If your road is newly built without good strength, or you have not added any gravel layer. Or your road will pass by many vehicles, you should apply another concrete layer over the filled geocells, maybe 10cm at least.

All in all, this can’t be simply answered with a single word. All of these require calculation. We can only offer suggestions based on our own experience.

Please understand this real situation!

Hi Claire, thank you for your detailed explanation, it was very helpful.

Let me give you more details about our project so you can guide us better.

This is a newly built internal road, made recently with an excavator, so the subgrade does not have strong support yet. At the moment, we have not placed a gravel layer, but we are considering it.

The road will be used mainly by cars and light vehicles, but there will be regular traffic inside the project.

Based on this situation, what would you recommend as the best solution?

Would it be better to:
1) Add a gravel layer under the geocell (and if so, what thickness do you suggest?), and then fill the geocell with concrete without an extra layer on top
or
2) Install the geocell directly and apply an additional concrete layer (around 10 cm) on top after filling it?

We want to ensure a durable solution but also optimize costs.

Thank you again for your support.

Combined with your project situation: new internal road, weak subgrade, no gravel layer for now, mainly for light vehicles with regular traffic. We give you the best solution for durability and cost saving.

We highly recommend Option 1:
First, lay a gravel layer under the geocell with a suggested thickness of 15-20cm, then compact and level the base. It will strengthen the weak subgrade and spread vehicle pressure for better overall stability.

Next, install the 75mm geocell and fix it tightly. Fill the cells fully with concrete and level the surface. No extra concrete layer on top is needed.

Additional notes:
Option 2 costs more and needs more construction steps. Without a gravel base, the soft new subgrade is easy to sink and crack in long-term use.

Adding a gravel layer is low-cost and easy to construct. The combination of gravel base, geocell, and concrete filling can fully meet long-term light traffic and greatly extend road service life. It is the most cost-effective choice.

In short, there is no single standard way for Geocell road construction. The plan must fit local subgrade, vehicle type and daily traffic. Proper gravel base and full concrete filling can balance cost and road strength. It ensures good stability and long use for light vehicles.

Excell Geocell shares real project cases and practical installation tips of Geocell. We provide clear technical support for global clients to help your projects run well.

After-Sales & Technical Support for HDPE Welded Geocell

Our post-sales technical assistance is a critical component for ensuring the success and long-term performance of your project. It is far more than just a basic after-sales service, it is a systematic and professional combination of technical services, primarily including the following core elements:

1. On-Site Installation Guidance

• First-Time Construction Guidance: We dispatch experienced technical personnel to the project site to provide hands-on practical training to the construction team for the initial installation, ensuring they master the correct procedures.
• Key Technical Supervision: We guide critical steps such as pre-installation preparations, foundation treatment, tensioning and positioning, anchor connection, and backfilling essentials to ensure the installation quality meets design specifications.
• Solving Installation Challenges: We provide customized installation solutions for complex terrain (e.g., steep slopes, uneven foundations).

2. Problem Diagnosis & Emergency Solutions

• Quality Anomaly Diagnosis: If issues such as geocell deformation, weld cracking, or local damage occur, our technical experts will conduct on-site or remote diagnosis to analyze whether the cause is related to materials, installation, or design loads.
• Providing Repair Solutions: We develop specific on-site repair plans and provide recommendations for necessary repair materials or tools.
• Incident Analysis & Reporting: For serious problems, we issue professional technical analysis reports to clarify responsibility and provide a basis for subsequent handling.

3. Technical Consultation & Design Optimization Support

• Application Consultation: We provide technical answers throughout the project lifecycle regarding the use of HDPE geocell in various applications (e.g., roadbed reinforcement, slope protection, load support, channel protection).
• Design Review & Optimization: Based on actual geological conditions and engineering requirements, we offer optimization suggestions for the original design, including geocell specifications (weld spacing, height, sheet thickness), installation methods, and anchoring techniques.
• Material Selection Advice: For special environments (e.g., extreme climates, chemically corrosive conditions), we recommend more suitable material formulations (e.g., models with enhanced UV resistance and weatherability).

4. Quality Inspection & Acceptance Support

• Quality Inspection: We provide product factory inspection reports and third-party test reports.
• Warranty & Claim Handling: During the warranty period, we assess, replace, or settle claims for components confirmed to have quality defects.
• Acceptance Support: Upon client request, we can assign personnel to assist with on-site sampling for testing or participate in joint quality acceptance inspections at critical construction stages, ensuring material and workmanship comply with specifications.

5.Long-Term Performance Monitoring & Maintenance Advice(For major or critical projects)

• Performance Monitoring Plan: We suggest or assist in establishing simple long-term monitoring methods (e.g., regular visual inspections, deformation checks).
• Maintenance Guide: We provide maintenance recommendations throughout the product’s service life to ensure its long-term effectiveness.

In summary, our high-quality after-sales technical support constitutes a full-process service system “from site to long-term.” The core objectives are: to ensure the product is correctly installed, performs as designed, addresses unexpected issues promptly, and ultimately guarantees the long-term stability and safety of the engineering project. When selecting a supplier, the comprehensiveness and responsiveness of its after-sales technical support system are crucial factors to consider, often even more important than the product price alone.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

Carbon Black vs. Hindered Amine Light Stabilizers (HALS)

If carbon black is a kind of Hindered Amine Light Stabilizer? The short answer is: No, carbon black is not a Hindered Amine Light Stabilizer (HALS).

They are two completely different types of substances with different ways of protecting materials (like plastics and rubber) from degradation caused by light (photo-degradation).

Here is a simple breakdown of their differences:

1. Carbon Black

• What it is: It’s a form of carbon and acts primarily as a Light Screener.

• How it works: Physical Protection.

  • It is black and very effective at absorbing and blocking UV light and visible light.

  • Think of it like an umbrella for the material. It creates a physical barrier that stops harmful UV rays from penetrating deep into the material, thus protecting it.

• Key Features:

  • Very effective and low-cost.

  • The main disadvantage is that it can only be used in black or dark-colored products.

  • Widely used in the rubber industry (e.g., tires) as both a reinforcing agent and an anti-aging agent.

2. Hindered Amine Light Stabilizers (HALS)

• What they are: They are specific organic compounds with a unique chemical structure.

• How they work: Chemical Protection.

  • They do not primarily work by absorbing UV light. Instead, they act as “scavengers” that capture and neutralize free radicals – the harmful molecules generated when the material is exposed to light, which are the main cause of degradation.

  • This is a complex chemical process that is very efficient and long-lasting.

• Key Features:

  • They are one of the most effective types of light stabilizers available.

  • The biggest advantage is that they do not affect the color of the product, so they can be used in transparent or light-colored items.

Summary and Comparison

Synergy:
Even though they are different, carbon black and HALS can sometimes be used together in industry to provide more comprehensive protection for a material, especially in harsh environments. However, they remain two distinct and separate types of additives.

In simple terms, Carbon black works by “blocking the light” (physical protection), while HALS works by “neutralizing the harmful chemicals” (chemical protection). They are two different classes of light stabilizers.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

What does HALS mean in the Geocell Industry?

In the geocell industry, HALS stands for Hindered Amine Light Stabilizers.

It’s a very important chemical additive used to protect geocells from breaking down due to sunlight exposure.

1. What is HALS?

HALS is a type of stabilizer that is mixed into the plastic material (usually polypropylene or polyethylene) when the geocells are being made.

2. What is its purpose? (Why do geocells need it?)

Geocells are used in outdoor construction projects like:

• Road and railway foundations

• Slope protection

• Embankment reinforcement

They are constantly exposed to sunlight, specifically the ultraviolet (UV) rays within it.

• Without HALS: UV rays have a lot of energy. They break the plastic’s molecular structure, causing the geocell to:

  • Become brittle and crack

  • Lose strength and load-bearing capacity

  • Change color and degrade on the surface
    This process is called “UV degradation.” A degraded geocell can fail, risking the entire project.

• With HALS: HALS acts like a powerful, built-in “sunscreen” for the geocell. It works continuously to:

  • Absorb and neutralize the harmful energy from UV rays.

  • Prevent the chemical reactions that cause the plastic to break down.

3. How does HALS work? (Simple Explanation)

HALS works as a “radical scavenger.”

1. UV light attacks the plastic and creates damaging particles called “free radicals.”

2. These radicals quickly spread, breaking more molecular chains and causing the material to weaken.

3. HALS effectively traps and neutralizes these free radicals, stopping the destructive chain reaction.

4. Importantly, HALS can re-generate itself after it works. This allows it to provide long-term protection for many years.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

Dynamic Modulus Testing for Geocells

1. What is it?

The Dynamic Modulus is a measure of a material’s ability to resist elastic (flexible) deformation under repeated, dynamic loads (like traffic). It is measured in Megapascals (MPa).

For geocells, this test does not measure the plastic sheet itself. Instead, it measures the overall stiffness of the “Geocell-Infill Composite”—the complete structure of the geocell filled with soil, sand, or gravel.

• Key Idea: When filled, a geocell becomes a strong, three-dimensional mattress. The dynamic modulus tells us how stiff and springy this composite structure is when subjected to repeated loads that simulate real-world conditions like moving vehicles.

• Difference from Static Modulus:

  • Static Modulus: Measured under a slow, constant load. It shows the final deformation.

  • Dynamic Modulus: Measured under fast, repeated loading. It better reflects the material’s long-term performance, resilience, and resistance to fatigue under actual use.

2. How is it tested?

The primary method is the Large-Scale Dynamic Triaxial Test, conducted in a laboratory.

Here’s a simple step-by-step breakdown:

1. Sample Preparation:

   • A geocell sample is cut to size, placed in a mold, and filled with the specified material (e.g., sand) in a standardized way.

2. Setup and Confinement:

   • The prepared sample is placed inside the test machine’s pressure chamber.

   • A constant confining pressure is applied all around it, simulating the pressure from overlying soil.

3. Applying Dynamic Load:

   • The machine applies a repeated, pulsating load on top of the sample, mimicking the action of vehicle wheels.

   • The frequency and strength of these pulses can be changed to simulate different traffic conditions.

4. Data Collection and Calculation:

   • Sensors precisely measure the applied dynamic stress (σ_d) and the resulting recoverable strain (ε_d—the elastic deformation).

   • The Dynamic Modulus (E*) is calculated using a simple formula:
     E* = σ_d / ε_d

3. What is the significance of the results?

The dynamic modulus value is crucial for engineering for several reasons:

1. Measures the Reinforcement Effect:

   • A higher dynamic modulus means the geocell composite is stiffer and stronger. It directly proves that the geocell successfully reinforces the infill material.

2. Provides Key Data for Modern Design:

   • It is an essential input for advanced road design software. Engineers use this value to accurately predict:

     • Rutting (permanent deformation)

     • Fatigue life of the pavement layers

   • This leads to safer, more cost-effective, and longer-lasting designs.

3. Predicts Long-Term Performance:

   • By seeing how the modulus changes over thousands of load cycles, engineers can assess the composite’s durability and resistance to fatigue over its lifetime.

4. Optimizes Material Selection and Cost:

   • Engineers can compare different geocells and infills to find the most cost-effective combination that meets the stiffness requirements.

5. Quality Assurance:

   • It serves as a high-level performance-based standard to ensure the delivered materials and construction will perform as designed.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

Which type of Geocell is suitable for Horse Paddock?

I have one customer in Europe who wants to use Geocell to build horse paddock, but they don’t know which type to use. Height use 50mm or 75mm? Welding distance use 250mm or 330mm? Textured or smooth surface? Perforated or Non-perforated type?

We have an important question regarding cell size. Here is for exemple a link of a US company that sells much smaller size cells. 

Do 330 mm cells provide sufficient bearing capacity for our intended use? We plan to develop strongly the use of geocells here and it is essentiel no mistaking in quality of what we provide to clients. Thanks for your sincere advice.

Please check all my answers below, then you will know the most suitable Geocell that for the application of horse paddock.

1, Geocell Welding distance

Our engineer said that 330mm and 356 mm welding distance definitely can provide sufficient bearing capacity. But for the application of horse paddock, the bearing capacity is not the most important thing we need to consider, because the horse hoof is very different from the tires of vehicle.

Due to the horse’s hoof being very small, the force is only locally applied. If a large cell size, local deformation is likely to occur. So the smaller the cell size, the better. As 250mm welding distance is the smallest for most Geocell manufacturers, so 250mm is the most popular type in the application of horse paddock.

2, Geocell Height/Depth

Our engineer said that for the application of horse paddock, most customers use 75mm, a few use 50mm, it is better to choose 75mm.

3, Use Perforated or Non-perforated type?

Our engineer said that due to the height of 50mm and 75mm is very short, then there is no need to use the drainage holes for cross drainage, and the bottom infill material is mostly gravel, which is also good for vertical drainage. At the same time, the non-perforated type Geocell has little damage to the sheet, which can lead to better tensile strength.

4, Install Geotextile under Geocell

Our engineer said that for installation, you must use Geotextile under the Geocell to prevent uneven settlement of fillers. As shown in the photo below:

5, The size of the gravel 

Due to the cell size of 250mm is very small, so in the installation stage, you need to control the size of the gravel(diameter better no more than 3cm and use different sizes for compaction).

All in all, our engineer recommends height 75mm, welding 250mm, thickness 1.5mm, textured and non-perforated is the most suitable type for your horse paddock application.

The expanded cell size for welding 250mm is 180x156mm, this is fixed. The expanded panel size can be produced as per your requirement, our regular size is 2.34×5.304m.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

Installing Geocell to protect Geomembrane

Recently, I received an inquiry from a customer in the Middle East, who wants to build an EFA pond which will be lined with geomembrane, and they plan to install Geocell on top of the Geomembrane to protect it. They want us to help with the Geocell Technical details and installation guidelines. For more details, please check below:

Our team is working on design of embankment with slope gradient of 1V:5H and slope height of 2.5m. As part of the slope protection measure and aesthetic requirements, we are proposing the use of geocells.

We need to understand the technical details and installation requirements of geocells on embankment slopes from your team. Thanking you in anticipation.

#Answer: Thanks for your below inquiry. This is Claire, have specialized in the HDPE Geocell field since year 2009. No problem, I can give you some recommendations.

According to your slope gradient of 1V:5H and slope height of 2.5m, we recommend to use our Excell Geocell HF100-445(height 100mm, welding distance 445mm), textured and perforated type. Attached please check our Tech-data for HF100-445, with all detailed specifications.

Dear Claire,

Thanks for sharing the design and installation guideline document.

To give you a brief insight of our project, please note that the embankment slope is for a proposed EFA pond which will be lined with geomembrane. The slope geometry shall be 1V:5H and with height of 2.5m.

#Answer: Ok, noted with thanks, the slope angle is around 11.3°.

Accordingly, we have put below our queries for your feedback.

1,How the J-hooks shall be installed in the presence of geomembrane liner below?

#Answer: No, for application of Geomembrane protection, you can’t use any Pin or Anchor, only use the tendon system to fix the Geocell.

Tendon+deadman design to fix the Geocell, and bury the deadman into the anchor trench.

2, Could you please share with us a typical cross section details used on actual project, where the geocell has been used underlain by geomembrane with geotextile protection?

#Answer: Sorry, we don’t have. As this kind of Geomembrane protection project is fewer than others, and no customer shares this similar design drawing with us.

3, What type of infill aggregate/gravel shall be used which does not impact the geomembrane liner below?

 #Answer: You should use Gravel selected to be free from sharp edges, your drawing also has emphasized this.

 And I checked carefully with our engineer, for Geocell type 100-445, the infill material of 75mm diameter stone is too big. You’d better use the diameter not bigger than 50mm, and in order to better compact them, we recommend to use 2-3 different kinds of sizes(For example, like dia 50mm + 20mm gravel together).

4, We have prepared below typical cross section. Could you please review our section and provide your recommendations/suggestions to include/remove any further details?

#Answer:  We have reviewed your design drawings, they are very professional and comprehensive, also the details clearly marked.  We only have 2 points want to emphasize:

• 1, The infill gravel size, better less than 50mm, and use 2-3 different kinds of size.
• 2, The tendon and deadman design, we will share other documents that have full details in next email separately.

To better help you understand the Geocell tendon and deadman design, I’d like to share below videos:

1, GEOWEB Slope Protection with Tendon & Clips Installation Guide Animation

https://www.youtube.com/watch?v=TxrcXbr4Kpw&list=PLjK2JehROsndYKa5-0RN_ZPYrTaQ7kafZ&index=2

2, GEOWEB Channel & Slope Installation (Full)

https://www.youtube.com/watch?v=1oQp3QsUl3w

3, GEOWEB Tendon Clips Installation

https://www.youtube.com/watch?v=F6bQTP5uh6g&t=36s

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.

Replacing the traditional slope reinforcement method with Geocell

I received an inquiry from a customer in Kyrgyz Republic, and my customer wants to reinforce their slope with Geocell, I checked all their requirements and answered all their questions. More details, please check them in below:

We are implementing the reconstruction project of highway. As part of this project, we are considering replacing the traditional slope reinforcement method (riprap) with more modern and efficient solutions, such as geocells.

Request for a Commercial Proposal

We are interested in obtaining the following information about your products:

1. Technical specifications of the proposed geocells suitable for slope reinforcement using standard bulk material.
2. Prices for the specified geocells.
3. Delivery terms to the Kyrgyz Republic, including delivery timeframes and possible supply volumes.
4. Our estimated volume is 7,400 m2. For this volume, should we consider an additional reserve when placing an order? If so, what percentage of extra stock do you recommend?

I checked all your requirements, please check my answers as follows:

1. Technical specifications of the proposed geocells suitable for slope reinforcement using standard bulk material.

#Answer: For application of slope protection, the most popular Geocell type is height 100mm or 150mm, welding distance 445mm.

As for the height to use 100mm or 150mm, it mainly depends on the slope angle and project budget. So what’s the slope angle of your project, could you please check and let us know? Then we can recommend you the most suitable Geocell type.

2. Prices for the specified geocells.

#Answer: As I said in the first question, we recommend to use Geocell height 100mm or 150mm and welding distance 445mm.

So I quoted you our best prices for HF100-445 and HF150-445, both GB standard and ASTM standard for your reference. The offer sheet will be sent in next email separately.

3. Delivery terms to the Kyrgyz Republic, including delivery timeframes and possible supply volumes.

#Answer: May I know where your project is? Generally we ship to our border, Turgart port or Irkeshtam port. Which port is much more near your project site? Please check and advise, then I will check the freight cost and quote you FOB price accrodingly. Currently, I quote you EXW price first.

4. Our estimated volume is 7,400 m2. For this volume, should we consider an additional reserve when placing an order? If so, what percentage of extra stock do you recommend?

#Answer: If you can tell us the exact slope width and length, then we can calculate and produce the best suitable expanded cell size for your projec.

In this way, the panel width and length are suitable for your project, easy for installation, then you don’t need to add the extra quantity.

Dear Claire,

Thank you for your prompt response and the provided quotation. We apologize for the delay in our reply. Below are our comments and additional questions:

1. Slope Angle: The slope angle we will specify the exact value and inform you additionally.

#Answer: I have checked your drawing, the slope is 1:1.5= slope angle 33.69°. For slope angle 33.69°, 100mm or 150mm height both are suitable, you can choose depends on your project budget.

2. Quotation: We appreciate the provided prices for geocell types HF100-445 and HF150-445 according to GB and ASTM standards.

#Answer: HF100-445 and HF150-445 are the most suitable and popular Geocell types for slope protection, we did a lot of slope projects with them all over the world.

Geocell for channel protection

3. Delivery Terms: Our project is located in the xxx  region; therefore, we request the delivery cost to the Torugart port.

#Answer: Ok, I’m checking the freight cost from our factory to Torugart port with our logistics, once get the cost, I will quote you FOB Torugart price accordingly.

4. Slope Dimensions: We will specify the exact length and width of the slope and inform you additionally.

#Answer: Ok, no problem, after get your exact slope length and width, then we can calculate and produce the most suitable expanded panel width and length that are best for your project.

5. Especially thanks for the photos and additional information regarding the geocells

As previously mentioned, any project modifications require approval from the consulting engineer. As the general contractor, we await their positive response, after which they will coordinate the changes with the design institute. This process is necessary to ensure all modifications comply with the project’s specifications and standards. We understand that the approval process can take time and may not always proceed swiftly, so we have to wait.

#Answer: I fully understand what you said and the project’s real situation, you don’t need to hurry and worry about me. I have full patience, because I have many customers get an order need 1 year, some big projects even need 2-3 years. Especially for Geocell, it is not easy to get a project, it needs complicated processes and procedures.

Good things take time, we do what we can, and let time do the rest : )

In continuation of our discussion, we are sending you section 9.11 of the project documentation, which describes the current methods of slope reinforcement using riprap. Due to difficulties in obtaining the required volume of stone, we propose considering the use of your geocells as an alternative solution.

#Answer:  Yes, Geocell fill with soil, then grass on the surface is more and more popular for slope protection projects. I will share you more projects that we did on WhatsApp.

Below is the relevant section of the project documentation for your reference:

#Answer:  Thanks for sharing, I will check it carefully.

______________________

9.11. Reinforcement Works, Drainage.
‘The embankment slopes, to prevent material from spilling into the riverbed, are supported by reinforced concrete retaining walls. The geometric dimensions and reinforcement of these walls are determined by calculations, with their length based on the bridge height.

Since the bridges are designed over mudflow channels, where mudflows periodically occur, to allow unobstructed passage of mudflows under the bridge and facilitate maintenance (channel clearing), the riverbed under the bridge and within the retaining walls is reinforced with 16 cm thick monolithic concrete over a metal mesh made of AI class reinforcement with a diameter of 8 mm and a mesh size of 200×200 mm.

The bottom and slopes of the artificial channel before and after the bridge are reinforced with stones of 0.5 m diameter, laid in a single layer with voids filled with smaller stones. (Here, we propose using geocells instead of riprap for reinforcing the bottom and slopes of the artificial channel.)

Drawings of the artificial channel structure and reinforcement lengths for each bridge are attached to the project.

Water drainage from the bridge deck is achieved through longitudinal and transverse slopes; water flows into concrete drainage trays leading to absorption wells.’

We hope this proposal is helpful and are ready to discuss possible project modifications to optimize the construction process.

We understand the importance of timely communication and assure you that any delays in our responses are not intentional. The current circumstances require careful coordination among all participants to maintain the project’s integrity and quality.

Once again, thank you for your understanding and continued support.

Any further questions, let Claire know freely. I’m the Geocell expert to answer any of your questions.

Based on my 15 years of experience in the Geocell field.