RE-CAST UTC Project Information

Project Title

Flexural Performance of Concrete Beams Strengthened using Different Repair
Techniques

Universities

Rutgers, The State University of New Jersey and New York University

Principal Investigator

Hani Nassif, P.E., Ph.D.
Rutgers, The State University of New Jersey and New York University

PI Contact Information

nassif@soe.rutgers.edu; 848-445-4414

C0-Principal Investigator

Kaan Ozbay, Ph.D.
New York University

kaan.ozbay@nyu.edu; 646-997-3691

Funding Source(s) and Amounts Provided (by each agency or organization)

New Jersey Turnpike Authority (NJTA) and/or New Jersey Department of Transportation (NJDOT) $115,119
RE-CAST $230,238

Total Project Cost

$340,357

Matching Agency ID or Contract Number

NJDOT/NJTA : TBD
RE-CAST: 00042134-01-2D

RE-CAST Grant Award Number

DTRT13-G-UTC45

Start and End Dates

Start Date: May 30, 2017
End Date: May 30, 2018

Brief Description of Research Project

The main objective of this research project is to evaluate the flexural performance of
reinforced concrete (RC) beams repaired and strengthened using four different techniques. The techniques are External Prestressing (EP) using various types of metallic and non-metallic tendons, Fiber-Reinforced Ferrocement Composite (FR-FC) thin sections, Fiber-Reinforced Self Consolidating Concrete (FR-SCC), and Fiber-Reinforced Polymers (FRP) sheets. These implementations have been widely used and implemented to upgrade existing structures (such as parking structures, concrete bridge beams and decks, pier caps, substructures elements, etc.) but at different loading conditions. The ultimate goal of this research is to comparatively investigate the efficiency of the proposed techniques when applied on small and large scale specimens under the same loading conditions. Deflection at several locations, load-carrying capacity, concrete and steel rebar strain, failure modes and crack patterns of the strengthened beams during testing will be measured, collected, and analyzed for comparison purposes. In addition to the experimental program, analytical models will be developed and calibrated based on test data, and the load carrying capacity for each strengthening method will be predicted. The obtained results of the proposed models can be used as input parameters in the analysis and design of strengthened members. This study will have three phases: 1) The first phase (which is almost completed using funds from NJTA) focused on upgrading the conventional Ferrocement and SCC mixes with steel and polypropylene fibers. Several trial mixes are prepared and strength and shrinkage test are performed. In addition, the mechanical properties of the sheets and the strands implemented in the repaired specimens will be evaluated; 2) The second phase include the application of proposed mixes and techniques on small scale and large scale reinforced concrete beam specimens in order to evaluate the effect of such techniques on the overall structural performance; 3) The final phase will focus on the finite element modeling of the tested specimens using ABAQUS and propose analytical models that will be applied to enhance equations and procedures in repair codes and to predict the beams capacity for design purposes.
At the end of this project, the team will use the outcomes of the material research namely,
deterioration functions and estimated costs to perform life cycle cost analysis (LCCA) with the
ultimate goal of optimal network-wide project selection. The team will make
recommendations to the NJDOT and NJTA for field implementation of the most promising
repair technique.

Describe Implementation of Research Outcomes

 The results for the strengthening methods investigated, External Prestressing (EP), Fibers
Reinforced Ferrocement Composite (FR-FC) thin sections mixes, Fiber reinforced SCC (FRSCC)
mixes and Fiber reinforced polymers (FRP) sheets, will be made available to local
transportation agencies. The results will help the local transportation agencies understand the state-of-the-art schemes to enhance and upgrade their own bridges using the best technique available based on the outcome for each system. Various techniques are applicable under different field conditions.

Impacts/Benefits of Implementation

 The proposed techniques in strengthening concrete beams are effective methodologies in
extending the service life of bridge deck and in making concrete infrastructures more durable
and sustainable.

Web Links

Project website: http://recast.mst.edu/projects/flexuralperformanceofconcretebeams/