UHPC inspires Awe for ones becoming newly familiar with the material. The immediate reason is its compressive strength, which at its lower threshold is about 150 MPa. With little effort that number can touch up to 250 MPa. No doubt, that is impressive! The reason we fall into the trap of asking about compressive strength is due to the word concrete in ‘Ultra-High-Performance Concrete’.
As one dives deep into understanding the material, one will quickly realize that UHPC is more of a composite than it is concrete. The reader will also notice ‘Ultra-High-Performance Concrete’ is missing the word ‘Strength’ in it. Instead, the word ‘Performance’ is the highlight of this composite material. A combination of tight particle packing of fine and ultra-fine powder and sand, high dosage of micro-fine steel fibers, and advanced chemical admixtures impart UHPC its ultra-high mechanical, durability, and flow properties – thus its superior performance to concrete.
The above results in ultra-high compressive strength, ductility in tension with strain-hardening, low creep, negligible deterioration in freeze-thaw, blast-resistance, high bond strength with reinforcing and prestressing steel, and high elastic modulus. On the durability side, as compared to Normal concrete, UHPC exhibits ultra-low chloride-ion penetration depth, ultra-low oxygen permeability, ultra-low water permeability, ultra-low reinforcement corrosion-rate, and ultra-low carbonation depth.
It is now easy to imagine the numerous applications both structural and non-structural that UHPC could be used for. There is more to UHPC than one can imagine. It fills an important gap between Concrete and Steel for the market. A material, which wasn’t is now there!
Written by – Dr. Satish Jain. MD, UHPC India Pvt Ltd.
About the author – Mr. Satish Jain is the owner & Managing Director of Satish Jain Consulting Engineers Pvt. Ltd, Mumbai and holds a M.S. degree in Civil Engineering from Iowa State University, USA. He is a licensed structural engineer in both the USA and India and has been involved with designing challenging structures across both countries. His expertise spans high-rise structures, unbonded post-tensioning, performance-based structural design and ultra-high performance concrete (UHPC). Mr. Jain’s current initiative involves promoting the use of UHPC in India through research & development, material development, application development, training, engineering and project management services.