| |
 |
|
High Performance Concrete (HPC)
The Need
|
Normal Strength Concrete (NSC) is heavy and
lacks the required workability in some large concrete structures, such as high-rise
buildings, bridges, and structures under severe exposure conditions. By increasing
concrete strength and performance, the required thickness of concrete members and the cost
of concrete structures can both be reduced. |
The Technology
|
High Performance Concrete (HPC) is the latest
development in concrete. It is not just High-Strength Concrete (HSC) and has replaced HSC
developed in the early 1980’s. HPC can be defined as a concrete made with appropriate
materials (superplasticizer, retarder, fly ash, blast furnace slag and silica fume)
combined according to a selected mix design and properly mixed, transported, placed,
consolidated, and cured to give excellent performance in some properties of concrete, such
as high compressive strength, high density, low permeability, and good resistance to
certain forms of attack. |
The Benefits
|
The benefits related to HPC include: early
stripping of formwork, greater stiffness, and higher axial strength. Therefore, it allows
the use of smaller columns. These factors combined lead to construction elements of high
economic efficiency, high utility and long-term engineering economy. |
Status
|
Several new technologies supporting HPC are on
the market now and have been used for several years. In Japan, the definition of HPC
combines self-placeable ability, durability and high strength. It is estimated that HPC
with these characteristics may be achievable within the next five to ten years. A
self-placeable concrete has been developed with the purpose of reducing construction site
labor and shortening construction time (see fact sheet on Self Placing Concrete). Several
projects have been successfully completed in Japan, and moreover, precast concrete plants
in Japan are preparing to take advantage of this new material to reduce noise from
vibrating machines. However, this new and significant technology has not received much
attention outside of Japan. In the U.S., a major
move toward HPC is underway, especially in the manufacturing environment of precast
concrete. A major demonstration precast concrete bridge is under construction in Texas. |
Barriers
- Current design criteria may not clearly define the
properties and usage of HPC. More research is needed in this area.
- Compared to Normal-Strength Concrete (NSC), the performance
of HPC is more brittle than NSC in regions with high seismic activity. This is due to the
greater stiffness of HPC.
- In some geographical areas, there is a Lack of suitable
strength aggregate required for HPC.
References
- Victor C. Li, “Construction Materials Development and
Application in Japan”, NMCEE Report No. 95-07, March 3, 1995.
- Stephen W. Forster, “High-Performance
Concrete-Stretching the Paradigm”, Concrete International.
Disclaimer Statement
|
Neither the Construction
Industry Institute nor Purdue University in any way endorses this
technology or represents
that the information presented can be relied upon without further investigation. |
SSL01
|
