|
VERY
HIGH-STRENGTH CONCRETE (VHSC)
|
|
 |
|
| U.S. Army Engineer Waterways Experiment Station
(WES) has been investigating and developing advanced concretes and binder
systems and construction placement technology to enhance the survivability
of permanent hardened facilities. The latest concrete to be developed and
evaluated is a very high-strength concrete (VHSC) containing steel fiber
reinforcement. Over 200 trail mixtures were evaluated in which the cementitious
materials, aggregates, water, admixtures, and steel fibers were varied.te.
A disadvantage of traditional high-strength concretes is their lack of significantly
enhanced ductility and tensile strength. The VHSC family of mixtures has
significantly improved ductility and tensile properties in addition to the
higher strengths. Using readily available materials, the flexural strength
of VHSC is approximately 10 times that of conventional strength portland
concrete (CSPC) and its tensile strength is over twice that of CSPC. The compressive strength of VHSC is approximately 7 times that of conventional concre. By using select materials, the compressive strength can be increased an additional 40 percent and the flexural strength can be increased an additional 90 percent. |
VHSC mixtures have been produced having compressive
strengths of 240 MPa and flexural strengths of 40 MPa. These significant
enhancements in the material properties of high strength concretes represent
a breakthrough in concrete technology. Targets were fabricated using the
VHSC for further evaluation in ballistic penetration experiments. VHSC samples
were also fabricated for use in mechanical property experiments to investigate
its response under complex states of stress and strain. Research to further
enhance the properties of VHSC is continuing. Beginning in 1996, WES begin
installing beams comprised various VHSC mixtures at Treat Island to conduct
freeze/thaw and seawater exposure studies. These beams represent variations
in developmental mixture designs. Representative cement types are as follows:
960022 - 960023, Class H Cement 960024 - 960039, Type 5 Cement VHSC1 - VHSC8, Class H Cement |