Asphalt vs. Concrete Blades: What's the Difference

When working with tough, abrasive construction materials like asphalt and concrete, selecting the correct cutting blade is paramount for efficiency, blade longevity, and safety. While diamond blades are used for both, asphalt blades and concrete blades are specifically designed with distinct characteristics to optimize performance for their respective materials.

Understanding the important differences between these blades is essential for anyone in construction, landscaping, or DIY. This guide will clarify why you need a specialized blade for each material and help you choose the right diamond blade for your project.

The Core Difference: Material Characteristics

The primary reason for specialized blades lies in the fundamental differences between asphalt and concrete:

• Asphalt: A softer, stickier, and highly abrasive material composed of aggregates (like sand and gravel) bound together by bitumen. It's often mixed with highly abrasive elements that can quickly wear down a blade's bond.
• Concrete: A harder, denser, and less abrasive material (unless it contains hard aggregates or rebar). It's typically more uniform in its abrasive qualities compared to asphalt.

These material differences directly influence the design and composition of their corresponding diamond blades.

Key Differences Between Asphalt and Concrete Blades

Let's break down the critical features that differentiate asphalt cutting blades from concrete cutting blades:

1. Blade Bond Hardness

The "bond" in a diamond blade refers to the metal matrix that holds the diamond particles in place. As the blade cuts, this bond wears away, exposing new diamond crystals that do the cutting.

# Asphalt Blade Bond-

• Composition: It contains a stronger metal bond, often incorporating metals such as cobalt and tungsten.
• Why: Asphalt's highly abrasive nature aggressively wears down the bond. A harder bond is needed to withstand wear and keep the diamond particles in place longer, thus preventing premature diamond loss. 
• Mechanism: The abrasive asphalt helps break down this hard bond at a controlled rate, ensuring new diamonds are exposed efficiently.

# Concrete Blade Bond-

• Composition: Typically uses a softer metal bond (often with metals like nickel and copper).
• Why: Concrete is generally less abrasive than asphalt. A softer bond allows for proper wear, ensuring new diamond crystals are continually exposed for effective cutting. If the bond is too stiff, it will become shiny and its cutting ability will be reduced.

2. Segment Design and Features

The design of the blade's diamond segments plays a crucial role in performance and durability:

# Asphalt Blade Design:

• Segment Undercut Protection: Often includes undercut protection or drop segments. These are specialized features (often wider or deeper diamond segments, or segments with a stepped design) to protect the steel core from abrasive wear.
• Why: Asphalt's rough and gritty composition can rapidly wear down the steel core of the blade just below the diamond segment. Undercut protection prevents this damaging effect, which helps to extend the life of the blade and maintain stability.
• Segment Height/Concentration: May have a higher concentration of diamonds or taller segments to withstand the increased wear.

# Concrete Blade Design:

• Segment Type: Typically features more uniform diamond segments without specialized undercut protection, as concrete is less prone to "undermining" the blade's steel core.
• Water Channels: Often designed with efficient water channels for wet cutting, which is common for concrete.

3. Price of the Blade

• Concrete Blade Price: Generally, concrete diamond blades can be higher in cost than dedicated asphalt blades, particularly for reinforced concrete blades. This is because concrete cutting often demands more precision, and blades for reinforced concrete require specific designs to handle rebar, which increases manufacturing complexity and material costs.
• Asphalt Blade Price: While dedicated asphalt blades are often more affordable than high-end concrete blades, they are still designed specifically for extreme abrasiveness and incorporate robust bond materials.

4. Versatility and Application Overlap

Can a concrete blade cut through asphalt? It's a common question.

• Concrete Blade on Asphalt: Yes, a concrete diamond blade can cut asphalt, but it's generally not recommended for extended use. Because concrete blades have a softer bond, they will wear down much faster when cutting abrasive asphalt. This results in a noticeable decrease in blade life and leads to poor cost-effectiveness. The bond will wear too quickly, losing diamonds, and the steel core may experience aggressive undermining.
• Asphalt Blade on Concrete: No, an asphalt blade is generally not suitable for cutting concrete. Their hard bond, designed for abrasive asphalt, will not wear down sufficiently when cutting harder, less abrasive concrete. This causes the diamond segments to glaze over and become dull, leading to inefficient cutting, excessive heat buildup, and potential damage to the blade and saw. The blade will stop cutting effectively long before its useful life is over.

Key Takeaway: While a concrete blade might get you through a small amount of asphalt in a pinch, it's inefficient. You cannot cut concrete effectively with an asphalt blade. For better performance, safety, and durability, always use the right specialized blade for the specific material. 

5. Application of Blade: Reinforced vs. Non-Reinforced

This point is specifically relevant to concrete blades:

• Reinforced Concrete Blades: These are designed with specific diamond compositions and segment designs to cut through concrete that contains rebar (steel reinforcement bar). They are typically more robust and come at a higher cost than blades designed for non-reinforced or "green" concrete.
• Non-Reinforced Concrete Blades: Designed for concrete without steel reinforcement. Using them on iron rods can damage the blade.

Conclusion

Both asphalt blades and concrete blade cutters are essential cutting tools for processing hard, abrasive construction materials. However, their different compositions, particularly the bond hardness and segment design, are specifically tailored to the unique characteristics of asphalt and concrete.

Understanding these differences is key to choosing the right diamond blades for your saw. Using the correct blade ensures efficient cutting, maximizes blade life, minimizes operational costs, and most importantly, enhances safety. For smaller projects, you can also cut concrete with angle grinder by fitting it with a diamond blade, though it is best suited for shallow cuts rather than heavy-duty work. Leading abrasive suppliers like Benchmark Abrasives offer a variety of specialized diamond blades for concrete and asphalt, ensuring you can find the perfect tool for your specific cutting needs.