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Title |
Study on Cracking Causes and Patterns in Median Barrier and Guardrail Concrete in RC Bridge
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Keywords |
중앙분리대 ; 방호벽 ; 콘크리트 ; 초기재령 균열 ; 소성수축 ; 소성침하 ; Median barrier ; Guide rail concrete ; Crack at early age ; Plastic shrinkage ; Plastic settlement |
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Abstract |
Concrete guide rail and median barrier are an attached RC member, however they are vulnerable to cracking due to slip form construction and large surface of member. In this study, causes and pattern of cracking are analyzed through assessment and NDT (Non-Destructive Technique) evaluation for concrete guide rail and median barrier on highway structure. For this work, analysis on drying shrinkage and hydration heat are performed considering installation period, and plastic shrinkage is also analyzed considering their environmental conditions. From the evaluation, plastic settlement around steel location, drying/ plastic shrinkage, and aggregate segregation are inferred to be the main causes of cracking in the structures. The crack causes and patterns are schematized and techniques of crack-control are suggested. Furthermore concrete guide rail/ median barrier in the bridge on the sea are vulnerable to cracking at early age so that special attentions should be paid at the stages of material selection and construction.
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