Title: Case Study in the Evaluation and Repair of ASR Deterioration in Concrete Bridge Beams

Author(s): M.E. Williams and D. Choudhuri

Publication: Symposium Paper

Volume: 277

Issue:

Appears on pages(s): 143-155

Keywords: alkali-silica reaction (ASR), concrete bridge beams, premature concrete deterioration

DOI: 10.14359/51682375

Date: 3/1/2011

Abstract:
This paper presents a case study in the evaluation and repair of precast prestressed concrete beams with moderate to severe deterioration due to Alkali-Silica Reaction (ASR). The subject of this study is a 25-year old, 15-span bridge in Texas experiencing deterioration characterized by longitudinal cracking along the bottom flange at the beam ends, vertical splitting in the beam web at the bearings, and general map cracking with discoloration on the beam surfaces. Evaluation methods discussed include crack and surface discoloration mapping and as well as procedures for excising samples for petrography and accelerated expansion testing to confirm the presence of ASR. A structural evaluation of the existing beams is also presented to study the potential capacity loss resulting from concrete deterioration. Detailed visual observations of distressed conditions, structural analysis of damage scenarios, and laboratory test results were considered to develop a repair course of action that included the application of crack fillers, concrete penetrating sealers, and coatings as well as the application of CFRP composites to confine the expansion in the concrete beams.