Mesh Reinforcement for Concrete Structures

Mesh reinforcement is a type of reinforcement in the form of a series of interconnected wires or bars arranged in a grid pattern. These meshes are used to reinforce and strengthen concrete structures like slabs, foundations, retaining walls, etc.

Image Credits: Walcoom

It's true, steel reinforcement is superior to mesh reinforcement in different ways. But there are situations where you really require mesh over rebars for your construction project, which not only saves time but also your money. 

This article outlines the different grades and features of mesh reinforcement for construction, along with situations you should employ mesh over steel rebars. 

History of Mesh Reinforcement

The mesh reinforcement system was derived back in the 20th century by German Engineer Eugen Schumann. The developed mesh consists of steel wires made from low-carbon steel woven together to create a mesh. This mesh system was inexpensive and easy to work with, which then became a popular way to reinforce concrete.

However, this reinforcement option got replaced during the mid-20th century by the use of thicker steel bars, now called rebars. Rebars then proved to provide greater strength and durability compared to mesh. But, this didn't end the era of mesh in construction applications. 

In recent years, modern mesh reinforcement systems are back to play and are available in a variety of materials like steel, fiberglass, and synthetic materials. These systems provide customized designs based on the needs of the project. 

There are mainly two types of mesh reinforcement used for concrete:

 

1. Welded Wire Mesh

Welded wire mesh, also known as welded wire fabric, is made of individual steel wires that are welded together to form a grid pattern. The wire used for welded wire mesh can be plain or deformed, and the spacing between the wires can vary based on the application. 

Welded wire mesh is commonly used for slabs, walls, and other structural elements. 

2. Expanded Metal Mesh

Expanded metal mesh is made by cutting and stretching a sheet of metal to create diamond-shaped openings. The resulting mesh has a high strength-to-weight ratio and can be used for reinforcement in concrete, as well as for cladding fencing, and other applications. 

Expanded metal mesh can be made from various metals, including steel, aluminum, and copper. It is often used for concrete slabs, walls, and other structural elements where a high level of durability is required.

Types and Grades of Mesh Reinforcement

 Mesh reinforcement can be made from various materials and the choice of the type depends on the application and design requirements. Here are some of the major types of mesh reinforcement based on material along with their standard codes and grades available. The data given below are based on American standards, ASTM and British Standards. 

1. Steel Mesh Reinforcement

This is the most common type of mesh reinforcement used in concrete construction. It is made from steel wires that are welded together to form a mesh pattern. Steel mesh reinforcement is available in various sizes and shapes, and can be made from different types of steel, including mild steel, high-tensile steel, and stainless steel.

Steel Mesh Reinforcement for Concrete Foundation

The standard codes for steel mesh reinforcement and respective grades in ASTM and BS standards are mentioned in the table below.

STANDARD	GRADE	DETAILS
ASTM A497/A497M	Grade 40 [280 MPa]	Standard specification for steel welded wire reinforcement, deformed, for concrete
	Grade 60 [420 MPa]
	Grade 80 [550 MPa]
ASTM A185/A185M	Type I - Welded wire fabric for general use	Standard specification for steel welded wire reinforcement, plain, for concrete
	Type II - Welded wire fabric for marine use
ASTM A1064/A1064M	Grade 40 [280 MPa]	Standard specification for carbon-steel wire and welded wire reinforcement, plain and deformed, for concrete
	Grade 60 [420 MPa]
	Grade 80 [550 MPa]
BS4482	B500A - 500 MPa characteristic strength	Specification for steel wire for the reinforcement of concrete
	B500B - 500 MPa characteristic strength
BS8666	A393 mesh - 10 mm wires at 200 mm centers	Specification for scheduling, dimensioning, bending and cutting of steel reinforcement for concrete
	A252 mesh - 8 mm wires at 200 mm centers
	A193 mesh - 7 mm wires at 200 mm centers

From the table above, it is clear that the grades vary based on whether the wires are welded, plain or deformed, or made from different steel types.

Read On : How to Snap Tie Reinforcement Bars for R.C.C Structures?

2. Fiberglass Mesh Reinforcement 

Fiberglass mesh reinforcement is made from glass fibers that are woven together to form a mesh pattern. It is lightweight, easy to handle, non-corrosive, and has high tensile strength. 

Fiberglass Mesh Reinforcement for Wall Construction

Fiberglass mesh reinforcement is commonly used in precast concrete products, such as pipes and tanks, as well as in architectural applications.

3. Synthetic Mesh Reinforcement

Synthetic mesh reinforcement is made from materials such as polypropylene, nylon, or polyester. It is lightweight, corrosion-resistant, and has good tensile strength. 

Synthetic mesh reinforcement is commonly used in applications where corrosion resistance is important, such as in marine and coastal environments.

Benefits of Mesh Reinforcement for Concrete

1. Increased Strength: Mesh reinforcement provides increased strength to concrete structures by distributing loads and stresses evenly throughout the concrete. This helps to prevent cracking and other forms of structural failure. 
2. Improved Durability: Mesh reinforcement helps to improve the durability of concrete structures by preventing cracking due to thermal expansion and contraction, as well as other types of damage caused by environmental factors such as water, wind, and sun exposure.
3. Cost-Effective: Mesh reinforcement is generally less expensive than other types of reinforcing steel. This makes it a cost-effective option for smaller projects or for applications where cost is a consideration. 
4. Ease of Use: Mesh reinforcement is easy to work with and shapes during the construction process. Its flexibility allows it to be easily molded into the desired shape without the need for specialized equipment.
5. Corrosion Resistance: Mesh reinforcement is made from galvanized or epoxy-coated steel, which makes it less prone to corrosion than other types of reinforcing steel. This helps to ensure the long-term durability of the structure.
6. Versatility: Mesh reinforcement can be used in a variety of concrete structures, including walls, floors, and foundations. Its flexibility and ease of use make it a versatile option for many different types of construction projects.

Mesh Reinforcement or Steel Rebars for Construction

When choosing between mesh reinforcement and steel reinforcement bars (rebar) for concrete, there are several factors that should be considered:

FACTORS TO CONSIDER	MESH REINFORCEMENT	STEEL REINFORCEMENT BARS
Load Requirements	Suitable for low to medium loads or stresses	Suitable for high loads or stresses
Construction Site	Easier to handle and install in areas with limited space or difficult access	More challenging to handle and install in areas with limited space or difficult access
Budget	Generally less expensive than steel reinforcement bars	Generally more expensive than mesh reinforcement
Design Requirements	Suitable for simple shapes and designs	More suitable for complex shapes and designs
Corrosion Resistance	Typically coated for greater corrosion resistance	May be more appropriate for applications where greater corrosion resistance is needed

De-Merits of Mesh Reinforcement

While mesh reinforcement has many benefits for reinforcing concrete structures, there are also some potential issues that should be considered:

1. Reduced Strength: Mesh reinforcement has a lower tensile strength than steel reinforcement bars, which means it may not be suitable for structures that will be subjected to high loads or stresses.
2. Inadequate Placement: Mesh reinforcement can be susceptible to improper placement or installation, which can lead to weak spots in the concrete structure.
3. Durability: While mesh reinforcement is typically coated to improve its resistance to corrosion, it may still be susceptible to rusting or other types of corrosion over time. This can lead to weakened concrete structures and reduced durability.
4. Compatibility: Mesh reinforcement may not be compatible with certain concrete mixes, which can affect the overall strength and durability of the structure.
5. Design Limitations: Mesh reinforcement may not be suitable for complex designs or shapes, as it is less flexible than steel reinforcement bars.
6. Difficulty in Cutting: Mesh reinforcement can be difficult to cut and shape on-site, which can make it more challenging to work with than steel reinforcement bars.

It is important to note that these factors are not exhaustive and that the final decision on which type of reinforcement to use will depend on the specific requirements of the project.

Read More On: Fiber Reinforced Concrete (FRC)