Improving the Safety of Rebar Cages by Using Innovative Connectors

Improving the Safety of Rebar Cages by Using Innovative Connectors

Rebar cages are the skeleton of reinforced concrete components commonly used in building construction. Deep foundations in many types of buildings and civil works utilize Cast-in-Drilled Hole (CIDH) piles and/or slurry wall foundations (SWF). The largest and heaviest rebar cages on the jobsite are those used in SWF and CIDH piles. A rebar cage collapse during their construction would create a critical safety hazard for construction crew, and subsequent legal litigation, construction schedule delays, and thus, excessive cost and losses. The industry currently lacks proper engineering design and detailing procedure to safeguard the stability of these rebar cages in various construction stages. This experimental research will examine the behavior of CIDH/SWF rebar cages using innovative mechanical connectors (U-bolts, threaded rod with plate, and wire rope connectors) during various types of loading conditions. Strength values of the various mechanical connectors will be published.

This information will be used to:
- Establish rapid assessment and safety evaluation for CIDH/SWF rebar cages.
- Develop a procedure to predict the distribution of the internal forces in CIDH/SWF cages during all phases of construction.
- Establish guidelines and better practices for constructing and handling CIDH/SWF rebar cages.

The results of this research will help inform industry design guidelines for fabrication and site handling of large rebar cages utilizing innovative mechanical connectors. The results of the proposed study will also be applicable to rebar cages of above grade columns.

• Grant Details

  Project

  Improving the Safety of Rebar Cages by Using Innovative Connectors

  Grantee

  Construction Institute | ASCE

  Category

  Construction Means and Methods

  Subcategory

  Concrete

  Grant #

  01-20

  Award Amount

  $245,240

  Grant Period

  January 2020 - October 2023

  Grant Status

  Complete

  Principal Investigators

  Hamed Ebrahimian, Professor, Ph. D., P.E., University of Nevada, Reno Ahmad Itani, Ph. D., P.E., S.E., University of Nevada, Reno

  Industry Champions

  Mark Bennier, Tanner Blackburn, Ray Fassett, Danielle Kleinhans, Katerina Lachinova, Justin Ramer, Vincent Siefert, Lyle Sieg, Peter Speire, Jeff Veilleux

• Resources / Downloads

  • Guidelines for Circular Rebar Cage Assembly with U-bolt Connectors
  • Research Summary: Application of U-bolt Connector for Improving the Safety of Rebar Cages

    Summary of research
  • Best Practice Manual for Circular Rebar Cage Assembly with U-bolt Connectors
  • Experimental Investigation of U-Bolt Connectors for Application in Rebar Cages

    ASCE Paper