Mechanical integrity and sustainability of pre-stressed concrete bridge girders repaired by epoxy injection - Phase III
Sponsor: Georgia Department of Transportation
Project Information
PI: Chloe Arson, Co-PI: Lauren Stewart
Students: Rebecca Tien
Dates: September 2017 - Feb 2019
Funding: $100,000
Summary
During pre-stress transfer, the bottom portion of steel-reinforced concrete girders is subjected to an important compression induced by the relaxation of tension in the bars, which opens longitudinal cracks along the horizontal axis. Reactions at the supports induce shear stress, which sometimes translates into additional diagonal cracks at the ends of the girders. During the subsequent lifespan of the girder, a variety of crack patterns can occur, including longitudinal (along the beam axis), transverse (perpendicular to the beam axis), and diagonal cracks. At present, there is a need to assess the mechanical integrity and sustainability of pre-stressed concrete beams during the entire life cycle of the built infrastructure, which includes crack propagation, crack reparation, and repaired crack aging with possible re-opening. As such, this three-phase research program seeks to develop modeling strategies to predict the behavior of cracked concrete repaired by epoxy. The subject of this technical report is the Phase III research effort, which includes the experimental characterization of materials and systems for the computational (Phase I and Phase II) model calibration and validation. Three main sets of experiments were conducted: (1) concrete and epoxy-repaired concrete cylinders in uniaxial compression and splitting tension, (2) mortar cylinders in uniaxial compression and splitting tension, and (3) “as-built” and epoxy-repaired concrete beams via three-point bending.