Coal Ash: Its Origin, Disposal, Use and Potential Health Issues

Millions of tons of coal ash are produced worldwide each year. EPRI and others have done extensive studies over many years of the nature of coal ash and its possible effects on the environment and human health. This Environmental Focus feature summarizes this information applicable regulations that govern the handling and use of coal ash and the benefits that can result from its use. EPRI concludes that the health risks from coal ash are minimal that the general public does not encounter coal ash in such proportions that it would present health risks and that radiation from fly ash and products made with fly ash is well below the Environmental Protection Agency s action standards. Further EPRI argues that use of fly ash as a recycled material can have economically and environmentally beneficial results.

Technical Report Author: Electric Power Research Institute (EPRI)

The Potential Use of Natural Pozzolans in British Columbia as Supplementary Cementing Materials

Based on a review of existing information the team examined the technical environmental and economic benefits and costs of using naturally pozzolanic materials from provincial deposits as compared with those associated with the use of fly ash from coal-fired thermal electrical power plants as a supplementary cementing material in British Columbia. Based on their findings the team concludes that there is no indication that the natural pozzolans from any of the identified sources in British Columbia have any apparent technical advantage relative to the fly ashes being imported into the province and used as portland cement replacement materials. Further in terms of the present supplementary cementing materials market in British Columbia there would be no environmental benefit derived from using a natural pozzolan instead of fly ash. Finally the delivered cost of a natural pozzolan suitable for use as a supplementary cementing material will be of the same order of magnitude but possibly higher than the price of fly ash in the Greater Vancouver Area market.

Consequently it is recommended that no further investigation of this issue be carried out by the EcoSmartâ„¢ Concrete Project until it can be demonstrated that there is a demand for portland cement replacement materials in the province that cannot be satisfied by the importation of fly ash form Washington State and/or Alberta at an acceptable cost.

Technical Report Author: Robert Gray, Ph.D., P.Eng., James Atwater, P.Eng., W. Dunbar, Ph.D., P.Eng., CMP Technologies Ltd.,

Potential for Reduction of CO2 Emissions in Canada Through Greater Use of Fly Ash in Concrete

The paper projects to the year 2010 the quantities of fly ash available for use in concrete in Canada and estimates the potential reduction of CO2 emissions associated with concrete production in three fly ash replacement scenarios. An inventory on a regional basis of fly ash economically accessible to Canadian cement and concrete producers is outlined. The paper presents the results of the projections and demonstrates that in a scenario where fly ash replaces 60% of cement in concrete beginning in 2000 very substantial CO2 emission reductions could be achieved contributing substantially to Canada’s efforts to reduce greenhouse gas emissions under the Kyoto protocol.

Technical Report Author: George Venta, P.Eng., Michael Nisbet, Ph.D., MBA

Designing Concrete and Concrete Structures for Sustainable Development

Global urbanization has placed huge demands on the construction industry in terms of the world s material and energy resources. Infrastructure regeneration and rehabilitation and cement and concrete materials have an undeniable part to play in enhancing the quality of human life. If we are to avoid global environmental degradation sustainable development of the cement and concrete industry has to be the foundation for all construction activity in the next millennium.

This approach demands that cementitious materials are manufactured for durability rather than for strength and that pozzolanic and other industrial cementitious byproducts are seen as vital and essential constituents of concrete. However sustainability in the construction industry will remain a pipedream unless design for specified durable service life is the basis for all future construction.

Technical Report Author: R.N. Swamy