A Sensitivity Study of Concrete Temperature Development in Bridge Foundations

摘要

The early age thermal development of concrete plays an important role in the durability of astructural concrete element. If the heat of hydration is not controlled the concrete element maybecome susceptible to thermal damage. The present study aims at developing recommendationsfor the construction of mass concrete. The research utilizes a computer program,ConcreteWorks, to analyze the thermal development of mass concrete elements. The computerprogram has been verified with data from the WB I-80 over the Missouri River Bridge.A sensitivity study has been conducted to determine the effect various construction,environmental, and mix proportion parameters have on the thermal development of Iowa massconcrete elements. Construction and environmental parameters that have been investigatedinclude dimensional size, fresh placement temperature, curing method, forming method, formremoval time, and placement date. Mix proportion parameters that have been investigatedinclude cement content, substitution of class C fly ash, class F fly ash, and GGBFS. The rangeof each parameter was developed to closely model Iowa mass concrete elements. The resultsshow that increasing the form removal time, reducing the dimensional size, reducing the freshplacement temperature, reducing the cement content, and the use of supplementary cementitiousmaterials has the largest influence on the thermal development of the concrete.