Long-Term Deflection Prediction and Correction of Creep and Shrinkage Model of High-Strength Concrete Based on Short-Term Measured Data for Bridge

Abstract

To investigate the laws of creep and shrinkage in high-strength, concrete for long-span prestressed continuous box-girder bridge and predict long-term deflection, strain sensors were embedded in the midspan of a box-girder bridge. The shrinkage strain of concrete was then directly measured, and the creep strain was obtained using the incremental algorithm of measured data. The measured data show that if the creep and shrinkage model in the existing specification is used, then the shrinkage effect is underestimated as a whole and the creep effect is overrated for the C55 high-strength concrete of the bridge. The long-term deflection is predicted using the modified prediction models of creep and shrinkage that are based on short-term measured data when the bridge is under dead load. The deflection prediction values of two modified prediction models were compared with the measured deflection. Results of the comparison indicate that the integrality of the short-term measured strain data in concrete, measurement accuracy, and modified prediction model that is based on the measured data influence the prediction accuracy of the modified prediction models.