ABOUT UHPC
The U.S. Federal Highway Administration (FHWA) defines Ultra High-Performance Concrete as a cementitious composite material composed of an optimized gradation of granular constituents, a water-to-cementitious materials ratio less than 0.25, and a high percentage of discontinuous steel fiber reinforcement. The mechanical properties of UHPC include compressive strength greater than 150 MPa and sustained post-cracking tensile strength greater than 5 MPa. UHPC has a discontinuous pore structure that reduces liquid ingress, thus significantly enhancing its durability as compared to conventional and high-performance concretes. Research has shown that the peak axial tensile strength of UHPC can range from 5 MPa to 11 MPa depending on the steel fiber type and content. UHPC exhibits high flowability, hence doesn’t require any compaction.
UHPC thus fills a critical gap between structural steel and concrete and opens new areas of applications in the design and construction of structures.
Dry Mix
Steel Fibers
Flow Test
Durability Comparison of UHPC to Normal and High Performance Concrete
RANGE OF UHPC MATERIAL PROPERTIES
| Property | Range |
|---|---|
| Compressive strength | 140 to 200 MPa |
| Tensile cracking strength | 6 to 10 MPa |
| Modulus of elasticiy | 40 to 70 GPa |
| Poisson's ratio | 0.2 |
| Coefficient of thermal expansion | 10 to 15 millionths/oC |
| Creep coefficient | 0.2 to 0.8 |
| Specific creep | 6 to 45 millionths/MPa |
| Total shrinkage | Up to 900 millionths |
Source: FHWA