Study on temperature in hydration heat and crack control of box beam concrete

Hydration heat in large concrete of box girder is always a difficult problem in bridge construction, if misconduct, the temperature crack will be formed easily. This article discussed the law of the temperature change in the early stage of hydration heat and the product mechanism of the temperature crack on the precast concrete box girder whose cross section is large and thick. This discussion is based on the monitor and analysis of the temperature and strain in a 60 metres span prestressed concrete box girder. According to the experimental data, the key to prevent and control the temperature crack is to reduce the temperature in hydration heat and the control of the temperature gradient of concrete. And united the latest experiences in bridge construction, the measures are proposed from the aspects of design, construction and maintenance in box beam and monitoring the temperature.