Investigating the Problem of Transverse Cracking of Bridge Decks

摘要

One of the biggest problems affecting s bridges is the transverse cracking andrndeterioration of concrete bridge decks. The causes of early age cracking arernprimarily attributed to plastic shrinkage, temperature effects, autogenous shrinkage,rnand drying shrinkage. The cracks can be influenced by material characteristics,rncasting sequence, formwork, climate conditions, geometry, and time dependent. Therncracking of bridge decks not only creates unsightly aesthetic condition but alsorngreatly reduces durability, leads to a loss of functionality, loss of stiffness, andrnultimately the loss of structural safety.rnThe experimental and field testing investigate the early age transverse cracking ofrnbridge decks and how to mitigate them. Our research identifies suitable materials forrncrack sealing showing their ability to span cracks of various widths and achievingrnperformance criteria such as penetration depth, bond strength, elongation, and typernof sealant. Sealant were field tested, on bridges and on slab samples, forrnperformance by chloride sampling cores or drill dust samples or water flooding ofrnthe treated deck areas to check water leak, core tests to determine the depth ofrnsealant penetration, use dissection/stereo microscopes to determine resin depth andrnfluorescent and long-wave UV lighting. The research finite element modelrninvestigates whether live-load deflection limits or vibration control are importantrnfactors in bridge deck cracking.rnThe research will also establish a database on bridge information, crack location,rnconcrete mix ingredients and properties, construction method, superstructure type,rnpossible causes for cracking, and other relevant data for selected bridges.