Effect of cover depth and rebar diameter on shrinkage behavior of ultra-high-performance fiber-reinforced concrete slabs

Doo Yeol Yoo, Ki Yeon Kwon, Jun Mo Yang, Young Soo Yoon

Research output: Contribution to journalArticle

2 Citations (Scopus)


This study investigates the effects of reinforcing bar diameter and cover depth on the shrinkage behavior of restrained ultra-high-performance fiber-reinforced concrete (UHPFRC) slabs. For this, twelve large-sized UHPFRC slabs with three different rebar diameters (db=9.5, 15.9, and 22.2 mm) and four different cover depths (h=5, 10, 20, and 30 mm) were fabricated. In addition, a large-sized UHPFRC slab without steel rebar was fabricated for evaluating degree of restraint. Test results revealed that the uses of steel rebar with a large diameter, leading to a larger reinforcement ratio, and a low cover depth are unfavorable regarding the restrained shrinkage performance of UHPFRC slabs, since a larger rebar diameter and a lower cover depth result in a higher degree of restraint. The shrinkage strain near the exposed surface was high because of water evaporation. However, below a depth of 18 mm, the shrinkage strain was seldom influenced by the cover depth; this was because of the very dense microstructure of UHPFRC. Finally, owing to their superior tensile strength, all UHPFRC slabs with steel rebars tested in this study showed no shrinkage cracks until 30 days.

Original languageEnglish
Pages (from-to)711-719
Number of pages9
JournalStructural Engineering and Mechanics
Issue number6
Publication statusPublished - 2017 Mar 25



  • Cover Depth
  • Degree Of Restraint
  • Rebar diameter
  • Shrinkage
  • Slab
  • Steel Rebar
  • Ultra-High-Performance fiber-reinforced Concrete

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Building and Construction
  • Mechanics of Materials
  • Mechanical Engineering

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