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EXAMINING THE EFFECTS OF MIXER TYPE AND TEMPERATURE ON THE PROPERTIES OF ULTRA-HIGH PERFORMANCE CONCRETE | ||||
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W. Micah Hale, Ph.D., P.E. Kirk A. Grimmelsman, Ph.D., P.E.
July 1, 2008 - June 30, 2009
Ultra-High Performance Concrete (UHPC) is a new type of concrete that holds much promise in the
areas of homeland security (specifically blast resistance structures) and transportation
structures (specifically bridges). When mixed and cured properly, UHPC can achieve compressive
strengths in excess of 30,000 psi compared to traditional concrete that has strengths that range
from approximately 4000 psi to 17,000 psi. The high compressive strength of UHPC is not its only
advantage, UHPC also has superior tensile strength, ductility, and durability. However, a special
type of concrete mixer (high shear mixer) is required for batching UHPC so that it can obtain these
superior properties. Researchers at the University of Arkansas have been the first and only University
to batch UHPC in a standard rotating drum mixer, however there has been no research conducted on the
effect of mixer type on UHPC’s properties. The objective of this research program is to examine the
effect of mixer type on the performance of UHPC. UHPC mixtures will be batched using a standard
rotating drum mixer, a high shear mixer, and a concrete ready mix truck. The fresh and hardened
properties of the UHPC will be measured for all mixtures. Additionally, the UHPC will be batched at
temperatures ranging from 10 C to 30 C to assess the effect of mixing temperature on UHPC performance.
Results from the research program will be used to develop mixing guidelines when UHPC is mixed using a
standard rotating drum mixer and at a range of temperatures. The research program will also determine
if the performance of UHPC is diminished when mixed in a standard mixer. If the results show that there
is little effect or no effect on concrete performance, the opportunities for UHPC (especially in field
casting) will increase which will result in longer lasting and safer structures.
TRB Keywords: High strength concrete.
Product: In Progress (MBTC-3012)
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