Iowa State University
Computer programs; Concrete bridges; Cracking; Mass concrete; Temperature
Recently, the Iowa Department of Transportation (Iowa DOT) sponsored a project (InTrans Project 10-384), Iowa Mass Concrete for Bridge Foundation Study (Shaw et al. 2011 and 2014). In the study, the construction observations and data from the WB I-80 and US 34 Missouri River Bridges, Iowa, were reviewed. The temperature, temperature differential, and cracking potential of these bridges were analyzed using two computer software programs: ConcreteWorks and 4C-Temp&Stress. The research indicates that Concrete Works, currently free to public, is much easier to use than the 4C-Temp&Stress computer program and capable of predicting the general trend of thermal development of mass concrete elements (focused on structural elements with a least dimension of 6.5 feet or less). The model results from Concrete Works can be used to assist in designing and optimizing mass concrete mix proportions, construction sequences, and temperature control plan. The InTrans Project 10-384 also indicates that although user-friendly, some features in the Concrete Works program do not fit Iowa concrete appropriately. For example, some units are in metric system, some default input data (e.g., materials and properties) are different from Iowa mass concrete materials and practice, there is no consideration of cooling pipe systems, the program provides limited temperature output up to 14 days and cracking potential up to 7 days only. The outputs do not provide sufficient information on the degree (e.g., stress-to-strength ratio) or probability of cracking. The software lacks of flexibility of creating new construction methods and editing outputs (Shaw 2012 and Li 2012). This proposed research is to evaluate, modify and adapt the ConcreteWorks software for Iowa's use (and potentially for other states in the US).