This study 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 with a spray dryer ash (SDA). Based on multiple-shake-table tests, the high content SDA frame was found to perform as well as the standard concrete frame for two earthquakes exceeding design-level intensity earthquakes. Hence, from a purely seismic/structural standpoint, it may be possible to replace approximately fifty percent of cement in a concrete mix with SDA for the construction of structural members in high seismic zones. This would help significantly redirect spray dryer ash away from landfills, thus, providing a sustainable greener alternative to concrete that uses only Portland cement, or only a small percentage of SDA or fly ash. 1. Introduction Ash is a byproduct obtained during the combustion of coal. Fly ash is generally obtained from the chimneys of coal-fired power plants. Depending on the amount of calcium, silica, iron, and alumina content of the ash there are two classes of fly ash as defined by ASTM C618, specifically Class C and Class F fly ash. Class C fly ash has high-calcium content, and its carbon content is usually less than two percent, while Class F fly ash has a low-calcium content with a carbon content usually less than five percent. Fly Ash, due to its pozzolanic properties is often used as an additive to Portland cement in concrete production. The use of fly ash in concrete increases the strength and durability of the concrete and also decreases the heat of hydration and permeability of the concrete. The use of fly ash in concrete helps to reduce environmental pollution, because for every ton of fly ash used to replace Portland cement in the manufacture of concrete, there is a reduction of carbon dioxide emissions which is, for example, equal to the amount of carbon dioxide generated from the average automobile during a two-month period [1]. Since the majority of SO2 emissions into the atmosphere are due to coal fired power plants, many coal fired power plants in the United States are now utilizing spray dry absorbers for the reduction of these SO2 gas emissions. The result is SDA which has material and behavioral properties similar to fly ash, but a different chemical makeup. In this process alkali sorbents such as lime (CaO) or calcium hydroxide (Ca(OH)2) are mixed with water to form an aqueous slurry [2]. This slurry is sprayed into the flue gas in a cloud of fine droplets. SO2 is then captured with this sorbent and is dried by the heat of the flue gases.
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