Difference between UHPC and traditional concrete?

21 Dec Difference between UHPC and traditional concrete?

Traditional concrete is used in almost all construction applications. But, under some demanding applications, it might fall short in durability and longevity.

This is why some builders use Ultra-High-Performance Concrete to address this issue.

Ultra-High-Performance Concrete (UHPC) is a concrete with high strength and durability. It’s resistant to wear and environmental factors. It achieves compressive strengths over 150 MPa. 

Hence, it’s used in demanding construction applications like bridges and industrial structures.

Wondering what UHPC is and how it is different than conventional concrete? In this article, we are going to talk about this in detail.

Composition of Traditional Concrete and Ultra-High-Performance Concrete

Before comparing both kinds of cement, let us talk about their compositions. Conventional concrete consists of ordinary Portland cement, coarse gravel, standard sand, and water. However, UHPC concrete is made of high-grade Portland cement, fine silica fume, and sand. Plus, it has steel microfibers and some special admixtures.

Key Differences Between UHPC and Traditional Concrete

Now that we know their composition, let’s compare them in various aspects:

Compressive Strength

Traditional concrete comes with a least compressive strength of between 25-60 MPa. On the other hand, the compressive strength of UHPC concrete is about 150 MPa.

In general, UHPC has 3-16 times the compressive strength of regular concrete. And that’s what makes it ideal for high-performance applications like bridges.

Tensile Strength

It’s yet another measure of finding the overall strength of concrete. Conventional concrete typically has a tensile strength of 400–700 psi. However, for the UHPC, you would get a tensile strength of up to 1400 psi.

This means that Ultra High-Performance Concrete can withstand higher stress without breaking. Plus, when it is applied to the structures, it can reduce 1/2–2/3 of the weight compared to normal concrete.

Freeze-Thaw Resistance

With different additives, the UHPC performs better in freeze-thaw cycles. This is because UHPC has a denser microstructure. This stops the water from getting in and affects its structural integrity. But, when exposed to moisture, traditional concrete shows a low freeze-thaw resistance. In fact, it starts to deteriorate after 28 freeze/thaw cycles.

Abrasion Resistance

Abrasion resistance is directly proportional to the presence of steel fibers. Because of a 0-3% increase in steel fibers, the abrasion resistance can be increased up to 146.02 h/(kg/m2). Conventional concrete resists less wear and tear because it contains fewer steel fibers.

Permeability

UHPC has lower porosity compared to regular concrete, making it less permeable. This is due to the presence of Superplasticizers. The dense matrix allows for less water absorption. Plus, micro-fillers fill voids between particles, which creates a compact structure.

Corrosion Resistance

It’s yet another important factor to consider in any long-term project. Regular concrete offers less corrosion resistance than UHPC. But you can increase its corrosion resistance with protective coatings.

Due to tighter microstructures in UHPC, the oxygen diffusion rate is very low. This means its corrosion rate would be way lower than conventional concrete’s. Hence, UHPC performs better for high foot traffic and environmental stress applications.

Lifespan

This aspect is important for long-term projects that may have to endure high pressure. Since conventional concrete starts losing strength in 28 cycles, it can last longer.

As per expert estimates, a structure with UHPC concrete may last up to 200 years. The best part about UHPC? Its disconnected pore structure blocks other deterioration mechanisms, including ASR (alkali-silica reaction). 

Cost

Normal concrete has an edge over UHPC for cost consideration. The commercially available UHPC can cost you 20 times more than the regular one. 

Plus, with more steel fibers, the costs may also increase. This is worth the price for commercial applications. Yet, for small construction projects, you can rely on traditional concrete.

Self-Compacting Ability

Self-compacting ability ensures uniform filling of molds. It can reduce defects and rework construction projects. UHPC naturally exhibits self-compacting properties due to its fine particle composition.

Further, it flows into intricate molds without any mechanical vibration. But, regular concrete may not fill the voids and molds the right way or even reinforce sections.

Sustainability

If you are looking for sustainability-oriented projects, UHPC can be a better choice. You can tweak it for improved sustainability. By reducing the cement concentration, you can lower the CO2 emissions.

Choosing the Right Material Among UHPC and Traditional Concrete

Even though UHPC performs better, does that mean that it’s ideal for all your projects? Understand that for different applications, you need different concrete. Let’s take a look at how to choose the right concrete.

Use UHP Concrete When

UHPC is the ideal choice for projects that need very high strength and long lifespan. This is because it excels in environments with extreme weather or heavy loads. Plus, its self-compacting ability makes it perfect for intricate molds.

Plus, its low permeability ensures minimal maintenance and long-lasting performance. It best suits applications like bridges, facades, and high-performance industrial components.

Use Traditional Concrete When

You must use traditional concrete as it’s a cost-effective choice for standard projects. This comes with a good compressive strength of 20-40Mpa. 

This is ideal for most residential and commercial projects. It is ideal when design flexibility is not a priority, and thicker sections are workable.

It may not be as durable or strong as UHPC, but it performs well in moderate environments. Its easy availability makes it practical for large projects with low-demanding applications.

Final Verdict

So, that’s all for comparing Ultra High-Performance Concrete and traditional concrete. We have discussed 10 important aspects for comparison that can help you make a decision. In most aspects, UHPC performance is better.

But, while choosing the right concrete, always consider applications and budget. For more long-term projects, you can rely on UHPC. Yet, for short-term and low-budget projects, traditional concrete is ideal. Lastly, to make the right decision, always consult an expert.