?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F11164%2F&rft.title=On+the+Repair+of+Impact+Damaged+Prestressed+Concrete+Bridge+Girders&rft.creator=Kasan%2C+Jarret+Lee&rft.description=Prestressed+concrete+(PC)+bridges+are+susceptible+to+catastrophic+damage+(often+from+over-height+vehicle+impact)%3B+the+extent+of+which+is+often+difficult+to+assess+until+it+has+progressed+to+the+point+of+collapse.+Impact+damage+occurs+when+a+vehicle%E2%80%99s+height+is+greater+than+the+vertical+clearance+between+the+roadway+and+overpass+and+the+vehicle+strikes+the+overpass.+Impact+damage+ranges+in+severity%2C+but+generally+does+not+cause+immediate+collapse+of+the+structure.+However%2C+when+untreated%2C+impact+damage+can+result+in+further+or+accelerated+deterioration+often+resulting+in+significant+prestressing+steel+corrosion.+%0D%0APerforming+a+structural+repair+requires+confidence+that+the+member+in+need+of+repair+is+behaving+as+anticipated.+In+doing+so%2C+the+member+should+be+viewed+from+a+perspective+different+than+conventional+engineering+assessment+practices.+For+example%2C+the+contribution+to+section+capacity+of+strands+which+have+been+exposed+or+severed+due+to+over-height+vehicle+impact+are+neglected+in+conventional+member+assessment.+This+assessment+practice+has+been+found+to+be+overly+conservative+because+strands+%E2%80%98redevelop%E2%80%99+their+prestressing+force+upon+entering+sound+concrete.+Furthermore%2C+due+to+the+unanticipated+composite+action+occurring+between+an+AB+girder+and+the+barrier+wall%2Fcurb+slab+assembly%2C+many+AB+members+that+conventionally+behave+uniaxially+are+behaving+asymmetrically+and+biaxial+bending+effects+must+be+considered+when+determining+flexural+capacity.+Additionally%2C+few+(often+one)+girders+are+damaged+due+to+the+localized+nature+of+impact-damage.+Therefore%2C+a+rating+factor+expression+was+developed+to+quantify+damage+to+individual+girders.+%0D%0AOverall%2C+this+dissertation+presents+new+approaches+to+the+assessment%2C+analysis+and+repair+of+PC+girders.+Employment+of+these+assessment+and+analysis+techniques+allows+for+more+accurate+quantification+of+in-service+member+behavior%2C+thus+allowing+for+the+most+appropriate+solution+(member%2Fbridge+repair+or+replacement)+to+be+selected.+This+approach+is+demonstrated+through+a+case+study+analysis+of+a+previous+experimentally+tested+girder.+Lastly%2C+an+approach+to+determining+repair+technology+limitations+(based+on+geometric+and+mechanical+constraints)+through+an+impact-damaged+AB+girder+repair+example+is+provided.%0D%0A&rft.date=2012-06-04&rft.type=University+of+Pittsburgh+ETD&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=http%3A%2F%2Fd-scholarship-dev.library.pitt.edu%2F11164%2F1%2FKasan_Dissertation_2012.pdf&rft.identifier=++Kasan%2C+Jarret+Lee++(2012)+On+the+Repair+of+Impact+Damaged+Prestressed+Concrete+Bridge+Girders.++Doctoral+Dissertation%2C+University+of+Pittsburgh.++++(Unpublished)++