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Fly Ash, Silica Fume, Slag, and Natural Pozzolans in Concrete: Proceedings of the Third International Conference presents the latest technological advances in the use of these extremely valuable mineral by products. This two-volume set of 83 papers explores in detail how you can conserve energy and resource while increasing your profitability. The first volume contains papers dealing with fly ash and natural pozzolans, and the second volume details the use of condensed silica fume and ferrous and non-ferrous slags. Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP114

Paper reports the accelerated carbonation test results to investigate the effect of replacement ratio of fly ash, initial curing period in water, and air content on the carbonation phenomena in concrete. Using these test results, equations for the prediction of carbonation depth of concrete with and without fly ash are proposed, and these effects are also evaluated by these equations. Furthermore, the accelerated carbonation test results are compared with natural exposure test results for 15 years, and a method to predict the carbonation depth of concrete with and without fly ash exposed to natural indoor conditions is proposed. Concrete with fly ash is affected by initial curing period in water rather than concrete without fly ash from the viewpoint of depth of carbonation and compressive strength. The higher the fly ash content of concrete is, the deeper is the depth of carbonation. Depth of carbonation can be evaluated by compressive strength of concrete cured in water for 28 days, irrespective of the fly ash content of concrete. Carbonation depth of concrete with and without fly ash naturally exposed indoors can be predicted by the equation obtained by the accelerated carbonation tests.

Copper slag, a by-product of copper production, contains large amounts of iron oxide and silicate. It is chemically stable and its physical properties are similar to that of natural sand. The physical and chemical properties of copper slag were investigated. Copper slag, in amounts of 20, 40, 60, 80, and 100 percent, was substituted for fine aggregate in cement mortar and concrete. The fineness modulus of the combination of copper slag and fine aggregate was roughly 2.6, the optimum fineness modulus for concrete mix design. At this value, workability was found to be satisfactory with minimal bleeding. Addition of copper slag also improved the strength of the concrete. When the substitutional amounts exceeded 80 percent, lower strengths were obtained, possibly due to the formation of ettringite. It was also found that the effect of copper slag on long term strength development was also dependent on the amount used and its fineness. It was concluded that copper slag could be used as a fine sand substitute for ordinary reinforced concrete.

Paper reports results of an investigation conducted to evaluate permeability, porosity, and the corrosion-resisting characteristics of fly ash concrete made with finely graded beach/dune sand and crushed limestone (typical aggregates used in the Arabian Gulf countries). The experimental program was designed to include concretes made with water-cement ratios in the range of 0.35 to 0.55. The effect of fly ash addition on water permeability, porosity, and pulse velocity was studied over a period of one year. Accelerated corrosion tests were carried out in the laboratory for a period of about 4 years to study the corrosion-resisting characteristics of these concrete mixes. Specimens were located in the exposure site to evaluate the effect of salt contamination on the corrosion of reinforcing bars in fly ash concrete. Time to cracking, weight loss of reinforcing bars, and pH measurements were also carried out on these specimens. Results show that fly ash incorporation in concrete improves its general quality. Fly ash concretes show significantly better performance than plain cement concrete mixes in terms of resistance against reinforcing bar corrosion. Also, fly ash concrete specimens contaminated with slats do not show a noticeable aggravation in the reinforcing bar corrosion process for 20 percent replacement and for a 9 month exposure period. Reaction between fly ash and calcium hydroxide does not reduce the pH value below the pH of pure saturated Ca(OH)2 solution (12.5), even after partial consumption of the calcium hydroxide by fly ash.

Approximately 400 x 106 of low-level radioactive alkaline salt solution will be treated at the Savannah River Plant (SRP) Defense Waste Processing Facility (DWPF) prior to disposal in concrete vaults at SRP. Treatment involves the removal of Ca+ and Sr+2 followed by solidification and stabilization of potential contaminants in saltstone--a hydrated ceramic wasteform. The release of chromium, technetium, and nitrate from saltstone can be reduced significantly by substituting hydraulic blast furnace slag for portland cement in the formulation designs. Slag-based mixes are also compatible with Class F fly ash used in saltstone as a functional extender to control heat of hydration and reduce permeability. A monolithic wasteform is produced by hydration of the slag and fly ash. Soluble ion release (NO-3) is controlled by the saltstone microstructure. Chromium and technetium are less leachable from slab mixes than cement-based wasteforms because these species are chemically reduced to a lower faience state by ferrous iron or other ions such as Mn in the slag and are precipitated as relatively insoluble phases, such as Cr(OH)3 and TcO2.