Investigation and Control of Cracks in Wet Joint of Concrete Box Girders

Abstract

To investigate the causes of cracks in wet joints of continuous concrete box girders, we performed in situ analysis of the temperature and strain field of wet-joint concrete for a sea-crossing bridge under construction in China after casting. We developed a numerical model to compare with the field tests. The numerical results agree well with those measured in the field. Thermal stress due to the heat of hydration in concrete is the main factor causing cracks, followed by concrete shrinkage. Furthermore, we investigated some measures to minimize and control the occurrence of cracks, such as optimizing the concrete mix ratio and lowering the casting temperature of wet concrete.