What are the types of geogrids and their uses?
Geogrids, a subclass of geosynthetics, are synthetic materials used in civil engineering for improving soil stability and reinforcing structures. While it is permeable, their primary function is not drainage. For certain uses, these mesh-like structures, made of polymers like polyester, polypropylene, or polyethylene, provide versatile strength and stability. When combined with the proper infill, geogrids, with interconnected tensile ribs, reinforce and stabilize by locking with underlying soil or aggregate. Geogrids are essential for stabilizing soft ground, increasing pavement durability, and reducing road thickness while maintaining strength. Geogrids are widely used in heavy-load and civil engineering projects such as retaining walls, highways, slopes, embankments, and erosion control, and even in agriculture. Geogrids exhibit remarkable tensile strength. In reinforcement applications, it can function similarly to steel rebar by carrying tensile loads, but it is not directly comparable to steel and concrete in overall material properties.
What are the different types of geogrids?
Geogrids materials are specifically designed for civil engineering needs and are available in different types. Most commonly geogrids are divided into two categories:
- Based on patterns
- Based on manufacturing.
Let’s look at them based on their patterns, how they are made, and what materials are used.
Types of geogrids based on pattern:
1. Uniaxial geogrids- Uniaxial geogrids, made from polyethylene or polypropylene, are built to handle tension in one direction, which suits them for carrying heavy loads over time. StrataGrid by Strata Geosystems is often used in embankments, retaining walls, and landfill liners, especially where the soil is weak or the terrain is sharply sloped. Its directional strength provides reliable reinforcement for both vertical and inclined structures. Uniaxial geogrids improve load delivery, which provides structural reinforcement. While they can offer slight surface stabilization, their primary role is not erosion control. By reducing the requirement of minus total and minimal earthquake, they can add stability of construction projects, improving stability and safety. Uniaxial geogrids are available in different grades to match specific infrastructure needs. StrataGrid Uniaxial (SGU) is one such option, used to strengthen soil in applications where stable support is essential.
Main features of this geogrid which makes it different from other geogrids are:
- StrataGrid is crafted from high-quality polyester yarn with exceptional strength and tenacity. The HT yarn is made from PET polymer having varied characteristics such as high molecular weight (>25000 g/ mol), low CEG number less than 30 and low creep.
- A UV stabilized unique Polymer Modified Bituminous (PMB) coating provides excellent environmental, chemical and mechanical properties.
- Its design reduces thermal exposure for PET fiber, prevents polymer decline and ensures low increase for optimal performance.
- It is available in strength up to 800 Kn/M and up to 5.7 meters width.
- Strata process ensures better quality, stability and dimensional stability.
- StrataGrid is ISO 9001-2015 certified.
2. Biaxial geogrids- Biaxial geogrids like StrataGrid biaxial (SGB) from Strata Geosystems are adaptable materials with similar strength in both directions. They are therefore perfect for managing pressures from different perspectives. Applications for them primarily include subgrade reinforcement, soil stabilization, and foundation reinforcement under pavements and working platforms. These geogrids help stabilize the mass of soil, which reduces the capacity for erosion, and increases the durability of subgrade. They can be adapted to width, length and aperture measurement to meet the needs of a given project.
What makes StrataGrid™ biaxial (SGB) unique?
The key features of StrataGrid biaxial (SGB) include:
- Exceptional tensile resistance at lower elongations, surpassing conventional solutions in the market.
- Offered in strengths from 20kN/m to 150kN/m and a width of 5m, this product delivers exceptional reinforcement for pavement base layers.
- Reduces pavement crust thickness, leading to faster and more efficient construction processes.
- It strengthens the structure, reduces settlement problems, and helps prevent soil failure—offering solid support at the base of embankments built over weak ground.
- Contributes to sustainability efforts by decreasing the carbon footprint associated with pavement construction.
Types of geogrids based on manufacturing:
1. Extruded geogrids- Extruded geogrids are created by stretching polypropylene sheets, producing high strength and stiffness in the elongated direction. They vary in strength and stiffness based on the size and shape of their openings and ribs. Geogrids create a strong base layer that distributes weight evenly, reducing stresses and improving load-bearing capacity. Their rigid ribs and thick walls lock aggregate materials, increasing resistance to sliding and movement. Extruded geogrids are available in uniaxial or biaxial forms, and they are used for railway trackbed stabilization, basal reinforcement of embankments, bridge and railway abutments, retaining walls, reinforced soil slopes, reinforced foundation over piles, and reinforcement of granular road base and sub-base.
2. Woven geogrids- Woven geogrids are created by intertwining high-tenacity fibers, which are typically polyester or polypropylene, into longitudinal and transverse ribs. These woven structures are then treated with a polymer coating, like PVC, acrylic, or bitumen, to provide protection and enhance dimensional stability. These geogrids are clothlike, with visible threads woven in horizontal and vertical directions, making them ideal for projects related to soil reinforcement, separation, and stabilization. They are used to enhance subgrade conditions and minimize the quantity of aggregate. Woven geogrids are commonly made of polymer materials such as polyester, polyvinyl alcohol, polyethylene, or polypropylene. It serve as a substitute for different types of geogrids, such as extruded geogrids, and find numerous applications in civil engineering and construction endeavors.
3. Bonded Geogrids- Bonded geogrids are created by joining strands at right angles and coating them with plastic. They are a grid or net -like with threads running both horizontally and vertically. These geogrids play a necessary role in modern geotechnics and construction. They stabilize soft or unstable substrate and strengthen the subgrade, improve load distribution and increase soil load-bearing capacity.
Different types of geogrids are used depending on the soil and project requirements. Woven, extruded, geocomposite, and newer eco-friendly forms each serve a purpose in stabilising ground and supporting structures where needed. Strata Geosystems provides reliable results for soil stabilization, earth retention, and soil erosion control projects utilizing geotextiles and geogrids, earth anchors, walls and slopes, turf reinforcement, revegetation, containment, and more. With our expertise in manufacturing top-quality geogrids since 2004, backed by cutting-edge technology and a commitment to sustainability, we empower you to achieve superior performance and longevity in civil engineering projects.