Multi-Factor Modified Creep Deformation Prediction of High-Performance Concrete Structures: A Case Study

Le résumé fourni par la source

The use of high-performance concrete is a common practice in the construction of large-span bridges, where creep deformation may exert a considerable influence. This article puts forth a practical calculation method for long-term creep deformation of concrete bridges, based on short-term laboratory creep tests and multi-factor modification methods. A case study of a large-span railway concrete cable-stayed bridge examines the prediction results in conjunction with the monitoring data derived from digital image correlation (DIC) and compares these with the existing specifications. The results demonstrate that the mid-span deflection predicted by the proposed model shows a high degree of agreement with the short-term measurements. Over a monitoring period of 247 days, the mean mid-span deflection is found to be 2.948 mm and the predicted value is 3.343 mm, giving a relative error of 11.8% relative to the measured mean, which is deemed acceptable in engineering practice. The deflection values at various long-term time nodes indicate that the existing specifications generally overestimate the effect of creep when the concrete types are not taken into account. Although the predictions of the CEB90 model are closest to the model proposed in this paper, they are still 56.8%, 75.4% and 82.2% higher in the mid-span deflection at 3, 10 and 20 years after completion, respectively.

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