Nebraska LTAP
Date of this Version
3-2020
Document Type
Article
Citation
Marcus, G., Wood, R., Kodsy, A. (2020). Synthesis of Repair Practices of Damaged Precast/Prestressed Concrete Girders. NDOT Research Report SPR-P1 (19) M090.
Abstract
Bridge girders are constantly subjected to various types of damage during their service life. There is currently limited knowledge or guidelines provided by the NDOT Bridge Office Policies and Procedures (BOPP) regarding the assessment and repair procedures of damaged precast/prestressed concrete girders. This report aims to develop a comprehensive repair manual for precast/prestressed concrete girders subjected to damage caused by over-height vehicular collision and damage located at the girder ends. Over-height vehicular collision damage typically occurs at the middle portion of the exterior girders and the primary concerns are focused on flexural deficiencies. Girder end damage can occur due to corrosion of prestressing strands or reinforcement, malfunctioning joints, or during deck/abutment replacement; where the primary concerns are focused on shear deficiencies. When damage occurs, the decision-making process regarding whether to repair, rehabilitate, or replace the girder is typically challenging. A literature review on the classification of damage and a proposed damage classification are presented for each damage type. Repair methods and procedures for each damage class are then presented for each damage type. Previous repair cases done by NDOT are documented and their performance is evaluated by visual inspection records. Ultimate limit state structural calculations are presented in the form of design examples to calculate the flexure or shear strength of the undamaged and damaged girder according to AASHTO LRFD. The ultimate flexure or shear strength of a strengthened girder using FRP wrapping is also presented according to ACI 440.2R-17 as a design example. Suggested material properties are presented for each repair method according to previous research work and previous NDOT repair cases.