Development of hybrid UHPC-NC beams: A numerical study

Majid M.A. Kadhim, Akram Jawdhari, Abheetha Peiris

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

The mechanical properties and durability of ultra-high performance concrete (UHPC) are superior to those of normal concrete (NC). However, because UHPC is much more expensive than NC, it must be used strategically to maximize its exceptional compressive strength and sustained post-cracking tensile strength. This study develops a finite element (FE) model that represents the behavior of UHPC beams in flexure. The model is validated using previous experimental research which included UHPC beams, both with and without steel fibers, and four different reinforcement ratios. What distinguishes this study from previous efforts is that it also leverages the validated UHPC FE model to evaluate the feasibility of a hybrid reinforced concrete beam composed of both UHPC and NC. Several methods of using UHPC and fabricating a hybrid beam are studied. For a reinforcement ratio (ρ) of 0.009, a hybrid UHPC-NC beam with only the middle 50% composed of UHPC (Lu/L = 0.5) achieves the same capacity as a beam made entirely of UHPC when the NC's compressive strength is 30 MPa or more. Using dowel bars at the UHPC-NC interface improves beam ductility and shifts the failure location away from the interface. An outward inclination (θ) of 45° at the UHPC-NC interface also improves ductility of the Lu/L = 0.5 hybrid beam. The novel hybrid UHPC-NC beam developed in this study thus obtains strength and ductility values similar to or better than those documented in beams made completely of UHPC, but at a much lower cost. Predictive equations are proposed to evaluate the ultimate capacity of the hybrid UHPC-NC beam, and the results are compared with FE analysis results.

Original languageEnglish
Article number111893
JournalEngineering Structures
Volume233
DOIs
StatePublished - Apr 15 2021

Bibliographical note

Funding Information:
The authors wish to thank Dr. Christopher Van Dyke from University of Kentucky for reviewing and editing the manuscript. The technical and financial resources received from University of Babylon in Iraq and Queen's University in Canada are appreciated.

Publisher Copyright:
© 2021 Elsevier Ltd

Keywords

  • Concrete
  • Design guides
  • Finite element
  • Parametric analysis
  • RC beams
  • UHPC

ASJC Scopus subject areas

  • Civil and Structural Engineering

Fingerprint

Dive into the research topics of 'Development of hybrid UHPC-NC beams: A numerical study'. Together they form a unique fingerprint.

Cite this