Comparison between Normal Concrete and Ultra High Performance Concrete

Abstract

Over the last twenty years, remarkable advances have taken place in the research and application of ultra-high performance concrete (UHPC), which exhibits excellent rheological behaviour’s that include workability, self-placing and self-densifying properties, improved in mechanical and durability performance with very high compressive strength, and non-brittleness behaviour. It is the ‘future’ material with the potential to be a viable solution for improving the sustainability of buildings and other infrastructure components. This paper will give an overview of UHPC focusing on its fundamental introduction, design, applications and challenges. After several decades of development, a wide range of commercial UHPC formulations have been developed worldwide to cover an increasing number of applications and the rising demand of quality construction materials. UHPC has several advantages over conventional concrete but the use of it is limited due to the high cost and limited design codes. This paper also aims to help designers, engineers, architects, and infrastructure owners to expand the awareness of UHPC for better acceptance.

Introduction

Joints are critical but often the weakest parts in bridge structures, responsible for transferring loads between superstructure and substructure. Pre-cast prestressed bridges typically use high-strength self-consolidating concrete (HS-SCC) for joints, while cast-in-place bridges use conventional concrete, which is less strong and durable. Ultra-High Strength Concrete (UHSC) is a promising new material to improve joint performance.

Silica fume (or micro silica) is a by-product of silicon and ferrosilicon alloy production, consisting of very fine, spherical particles with strong pozzolanic properties, widely used to enhance concrete performance. It was first tested in Portland cement concrete in the 1950s and is used to replace 0-15% of cement to improve strength.

Chemical composition of silica fume varies with the production process but remains relatively consistent from a single source.

Properties: Silica fume particles are extremely fine (0.1-0.2 microns) with a large surface area, making it an effective concrete additive to improve compressive strength, durability, and reduce permeability.

Objectives of using silica fume in concrete:

• Enhance compressive strength and durability.

• Optimize the percentage for maximum strength.

• Reduce segregation and bleeding.

Advantages: Material reduction, increased lifespan, sustainability, and reduced permeability.
Disadvantages: Higher material and labor costs, need for specialized equipment, and curing difficulties.

Methodology:

• High-strength cement with low alkali content and fine aggregates were used.

• Silica fume replaced 20% of sand.

• Low water-cement ratio (<0.25) for better strength.

• Controlled mixing temperature (20-25°C).

• Specialized casting, curing, and testing procedures to optimize UHPC properties.

Results:

• Normal concrete showed compressive strengths around 19–26 N/mm² after 7–28 days.

• UHPC concrete showed higher strengths ranging from 15 to 30 N/mm² in the same period, demonstrating superior performance.

Comparison between Normal Concrete and UHPC:

UHPC with silica fume significantly improves strength and durability, making it ideal for critical structural elements like bridge joints.

Conclusion

Ultra-High Performance Concrete (UHPC) has demonstrated exceptional mechanical and durability properties, making it an ideal material for various structural applications. With its unique combination of high strength, toughness, and sustainability, UHPC offers numerous benefits over traditional concrete, including: 1) Enhanced structural integrity and safety 2) Reduced material usage and environmental impact 3) Improved durability and lifespan 4) Increased design flexibility and architectural possibilities

References

[1] AASHTO (American Association of State Highway and Transportation Officials), 2012, LRFD Bridge Design Specifications, 6th edition, Washington, DC. [2] ACI 318-11, “Building Code Requirements for Structural Concrete and Commentary,” 2011. [3] ACI Committee 239, “Ultra-High Performance Concrete,” 2011. [4] ASTM C29, “Standard Test Method for Bulk Density (“Unit Weight”) and Voids in Aggregate,” American Society for Testing and Materials Standard Practice C39, Philadelphia, PA, 2016.

Copyright

Copyright © 2025 Prapti Suryawanshi, Swapnali Suryawanshi, Sakshi Bagehalli, Sakshi Chavan, Prof. Mantri P N. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.