Temperature Boundary Condition Models for Concrete Bridge Members

Abstract

The authors discuss the strong dependency of mass concrete elements' temperature development on mixture proportions and constituent materials, as well as environmental conditions, geometry, and formwork type. The authors present an accounting method for convection, radiation, and shading effects on mass concrete surface temperature. Formwork radiation, surface-emitted radiation, atmospheric radiation, and solar radiation exchange were considered. In the convection model, surface roughness, ambient temperature, and wind speed were included. A mass concrete temperature prediction model incorporated the described model. Measured near-surface concrete temperatures were then compared with predicted temperatures. The authors also examined model ability to predict maximum temperature and maximum temperature difference. Results show that of the 12 concrete members instrumented, maximum temperature, maximum temperature difference, and near-surface concrete temperatures are accurately estimated through the model.