Shake table testing of concrete portal frame with high spray dryer ash (SDA) content
Date
2010
Authors
Rudraprasad, Karthic Rechan, author
van de Lindt, John W., advisor
Atadero, Rebecca, committee member
Senior, Bolivar, committee member
Journal Title
Journal ISSN
Volume Title
Abstract
Significant research has been conducted in replacing part of the cement content in concrete by fly ash. This thesis presents the method and results of an experiment to study the seismic behavior of a concrete portal frame with fifty percent of its cement content replaced by a spray dryer ash (SDA), which is similar to fly ash, obtained from the Platte River Power Authority’s Rawhide power plant in Northern Colorado. The behavior of the SDA portal frame under dynamic earthquake load is compared to the results obtained for the seismic behavior of ordinary Portland cement concrete. The portal frame is designed to represent the bottom story of a three-story office building in a high seismic region, e.g. Los Angeles, California. A mid bay portal frame is selected as a prototype frame and four similar 1/3 scaled down models of this frame were constructed. Two frames were constructed with fifty percent SDA concrete and the other two frames were constructed with ordinary Portland cement concrete. The frames were tested on the uniaxial shake table at the Colorado State University (CSU), Engineering Research Center (ERC), by placing two frames of the same mix type parallel to each other for stability. The scaled seismic mass is then placed on the frame and the instrumentation is installed. The concrete frames were tested first and then the SDA frames were tested using the same successive ground motions. Damage levels, and displacement response were recorded for each earthquake for both the tests and the results were compared. The basic premise of this thesis is to determine if a high SDA content frame sustains approximately the same amount of damage as a conventional concrete frame. By the results obtained from this study it has been shown that SDA frame may be considered to perform well, but not as good as conventional concrete frame. There was no significant damage or structural failure such as a collapse exhibited by the SDA frame when compared to that of conventional concrete frame. Hence about fifty percent of cement in concrete mix could be replaced by SDA for the construction of structural members in high seismic zones which leads to more economical buildings that help sustain the environment by redirecting spray dryer ash away from landfills.
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Print version deaccessioned 2022.
Print version deaccessioned 2022.
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Subject
Concrete -- Additives
Fly ash
Concrete construction -- Testing
Concrete construction -- Earthquake effects