Fly Ash Composites, A Step toward Pond Ash Composites

Abstract

The study demonstrated that ash composites made from polyurethane and fly ash are able to reduce leaching of coal ash inorganics to less than one-third of the U.S. Environmental Protection Agency\'s maximum containment limit even after being exposed to an accelerated water circulation system for 14 months. Even if these ash blocks are broken, the composite is safe. The concept of encapsulation of fly ash into ash composite by using a polar polymer to bind the fine inorganic particles, as nature has done in the original unburned coal, makes the ash composite safe. The ash composites have compression and flexure strength and surface hardness suitable for many engineering applications such as building products and infrastructure products that are more valuable than the use of ash in concrete. The application examples demonstrated include reusable ash storage blocks, utility pole crossarms, and building products such as chair railings, base boards, and decorative moldings. In addition, there are many more positive attributes of ash composites such as insect and fire resistance, low electrical and thermal conductivities, and low coefficient of thermal expansion. These properties need to be assessed further. This fly ash\--composite technology will be expanded to include pond ash that is very abundant in the United States and worldwide and has very limited use. Other applications such as electric poles, railroad ties, and highway sound barriers are the products for exploration.