Bridge Analysis, Design and Repair
343582 - Analysis of Cracking Caused by Hydration Heat in Innovative Massive Concrete Mixtures
Saturday, April 21
10:00 AM - 11:30 AM
The goal of this study is to create appropriate thermal and structural analysis models for assessing thermal stress and cracking in massive concrete structures when innovative or unconventional concrete mixtures are considered for design. Current study, funded by the Georgia Department of Transportation (GDOT), investigates thermal modeling techniques, applying theory to practice, in order to control thermal cracks caused by hydration heat in mass concrete structures. Thermal cracking is detrimental to the long-term durability of massive concrete structures. In the proposed analysis approach, the primary forms of heat transfer are conduction, convection due to weather variations, and solar radiation as well as an internal heat generation from the heat of cement hydration. Subsequently, a structural model is developed to import a nonlinear temperature profile from the thermal model in order to perform a nonlinear cracking analysis of structures based on real-life boundary conditions found in GDOT’s massive concrete structures such as bridge piers and foundations. It is concluded that the proposed analysis approach is exceptional in evaluating the effect of innovative and unconventional concrete mixtures that are optimized to control the maximum temperature and temperature variations in mass concrete structures. It is also concluded that the proposed thermal-cracking analysis process is highly efficient and practical to streamline the thermal and structural evaluations and thus investigate mass concrete mixtures by analysis without loss of accuracy. The analytical results are validated against experimental data. Structural engineers are generally not familiar with the heat transfer theory and thermal analysis. This topic is of regional, national, and international interest and provides structural engineers that design and analyze massive concrete structures a practical solution to thermal-cracking problems. Furthermore, structural engineers will be able to learn how to perform a transient thermal analysis and improve the design-by-analysis procedure when designing mass concrete structures such as concrete foundations and large bridge piers.