Shrinkage of Fiber-Reinforced Ultrahigh Strength Concrete

Abstract

The ultra-high strength concrete (UHSC) used in this study had a compressive strength greater than 145 MPa and was produced using materials commonly available in southern New Mexico. Specifically, locally available Type I/II cement, local sand with a top size of 600 μm, silica fume, steel fibers (13 mm long), and high-range water reducing admixture were used to produce the UHSC mixture with a water-to-cementitious materials ratio of 0.20. UHSC specimens were heat cured in a water bath at 50°C, and then removed from the water bath and dry cured at 200°C for two days prior to strength testing. This paper presents a combination of early age and longer term shrinkage measurements of UHSC that were used to characterize the total shrinkage that occurred during the curing process. Total shrinkage of fiber reinforced UHSC specimens that occurred during 30 days was 3,006 µ, with early age shrinkage (first 24 hours) contributing 58.5% of the total shrinkage.