What is Rebar? Types, Uses, and Sizes Explained

When you look at a concrete bridge, a towering skyscraper, or even a simple house foundation, the strength you see doesn’t come from concrete alone — it comes from what’s inside it. That hidden strength is rebar, short for reinforcing bar, a vital material that gives concrete its ability to bear tension and maintain structural integrity.

In this article, we’ll break down what rebar is, explore its different types, uses, and standard sizes, helping you understand why this steel product is indispensable in modern construction.

What is Rebar?

Rebar is a steel bar or steel mesh used to reinforce concrete and masonry structures. Because concrete is strong in compression but weak in tension, rebar provides the necessary tensile strength to prevent cracks and structural failure.

Rebar is typically made from carbon steel, featuring ridges or deformations on its surface to improve bonding with concrete. These ridges allow the steel and concrete to act together as a single structural unit, distributing loads more effectively.

Why Rebar is Important

• Enhances Strength: Rebar increases the tensile and shear strength of concrete.

• Prevents Cracks: Helps control cracking due to shrinkage or temperature changes.

• Improves Durability: Structures last longer and can handle greater loads.

• Supports Design Flexibility: Enables the construction of complex architectural forms and tall structures.

Types of Rebar

There are several types of rebar available in the market, each designed for specific structural and environmental requirements. Below are the most common types used worldwide:

1. Mild Steel Bar (MS Bar)

• Smooth surface without ridges

• Low tensile strength compared to deformed bars

• Used in light construction and temporary structures

• Easy to bend and cut

2. Deformed Steel Bar (Ribbed Bar)

• Features surface ribs for better bonding with concrete

• Commonly used in all types of reinforced concrete structures

• Available in various grades such as Grade 40, Grade 60, or 500MPa

• Also known as Hot Rolled Deformed Bar

3. Epoxy-Coated Rebar

• Coated with epoxy resin for corrosion resistance

• Ideal for marine environments or bridges exposed to saltwater

• Green-colored coating is a common identifier

4. Galvanized Rebar

• Zinc-coated surface for long-term protection against rust

• Offers superior corrosion resistance compared to epoxy-coated bars

• Commonly used in coastal or high-humidity areas

5. Stainless Steel Rebar

• Excellent corrosion resistance and long service life

• Used in high-value structures like tunnels, bridges, and marine platforms

• Higher initial cost but lower lifetime maintenance cost

6. Glass Fiber Reinforced Polymer (GFRP) Rebar

• Non-metallic and corrosion-free

• Lightweight and non-conductive

• Used in projects where magnetic or electrical interference must be minimized

Common Uses of Rebar

Rebar is used in nearly every concrete structure around us. Here are the most frequent applications:

• Building Foundations: Reinforces load-bearing footings and slabs.

• Bridges and Tunnels: Provides tensile strength against bending and vibration.

• High-Rise Buildings: Ensures stability in vertical columns and beams.

• Roads and Pavements: Prevents cracking under heavy vehicle loads.

• Retaining Walls and Dams: Enhances resistance against water pressure and soil movement.

Rebar Sizes Explained

Rebar comes in standard diameters measured in millimeters (mm) or inches, depending on the region. In most countries, the size of rebar is indicated by its nominal diameter or bar number.

How to Choose the Right Rebar

When selecting rebar for a project, consider the following factors:

• Environmental Conditions: Use coated or stainless rebar in coastal or humid areas.

• Design Load: Heavier loads require higher grades and larger diameters.

• Budget: Mild steel is cost-effective, while stainless or GFRP is ideal for long-term durability.

• Local Standards: Always comply with ASTM, BS, or local engineering codes.

Rebar may be hidden inside concrete, but it is the unsung hero of construction. It ensures that concrete structures remain strong, durable, and safe under tension and load. Whether it’s a small home foundation or a massive bridge, choosing the right type, size, and grade of rebar makes all the difference in structural performance.

At Shineyond Group, we supply a full range of high-quality steel rebars, meeting international standards and tailored to your construction needs.