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The characteristics of cement kiln dusts (CKDs) and their effects as partial replacement of Portland Cement (PC) were studied in this research program. The materials used in this study were two different types of PC (normal and moderate sulfate resistant) and seven CKDs. The CKDs used in this study were selected to provide a representation of those available in North America from the three major types of cement manufacturing processes: wet, long-dry, and preheater/precalciner. Two fillers (limestone powder and quartz powder) were also used to compare their effects to that of CKDs at an equivalent replacement of PC. It was found that CKDs can contain significant amounts of amorphous material (>30%) and clinker compounds (>20%) and small amounts of slag and/or flyash (<5%) and calcium langbeinite (<5%). The study found that CKDs from preheater/precalciner kilns have different effects on workability and heat evolution than CKDs from wet and long-dry kilns due to the presence of very reactive and high free lime contents (>20%). The blends with the two CKDs from preheater/precalciner plants had higher paste water demand, lower mortar flows, and higher heat generation during initial hydrolysis in comparison to all other CKD-PC blends and control cements. The hardened properties of CKD as a partial substitute of PC appear to be governed by the sulfate content of the CKD-PC blend (the form of the CKD sulfate is not significant). According to analysis of the ASTM expansion in limewater test results, the CKD-PC blend sulfate content should be less than ~0.40% above the optimum sulfate content of the PC. It was also found that the sulfate contribution of CKD behaves similar to gypsum. Therefore, CKD-PC blends could be optimized for sulfate content by using CKD as a partial substitute of gypsum during the grinding process to control the early hydration of C3A. The wet and long-dry kiln CKDs contain significant amounts of calcium carbonate (>20%) which could also be used as partial replacement of limestone filler in PC.

The characteristics of cement kiln dusts (CKDs) and their effects as partial replacement of Portland Cement (PC) were studied in this research program. The materials used in this study were two different types of PC (normal and moderate sulfate resistant) and seven CKDs. The CKDs used in this study were selected to provide a representation of those available in North America from the three major types of cement manufacturing processes: wet, long-dry, and preheater/precalciner. Two fillers (limestone powder and quartz powder) were also used to compare their effects to that of CKDs at an equivalent replacement of PC. It was found that CKDs can contain significant amounts of amorphous material (>30%) and clinker compounds (>20%) and small amounts of slag and/or flyash (<5%) and calcium langbeinite (<5%). The study found that CKDs from preheater/precalciner kilns have different effects on workability and heat evolution than CKDs from wet and long-dry kilns due to the presence of very reactive and high free lime contents (>20%). The blends with the two CKDs from preheater/precalciner plants had higher paste water demand, lower mortar flows, and higher heat generation during initial hydrolysis in comparison to all other CKD-PC blends and control cements. The hardened properties of CKD as a partial substitute of PC appear to be governed by the sulfate content of the CKD-PC blend (the form of the CKD sulfate is not significant). According to analysis of the ASTM expansion in limewater test results, the CKD-PC blend sulfate content should be less than ~0.40% above the optimum sulfate content of the PC. It was also found that the sulfate contribution of CKD behaves similar to gypsum. Therefore, CKD-PC blends could be optimized for sulfate content by using CKD as a partial substitute of gypsum during the grinding process to control the early hydration of C3A. The wet and long-dry kiln CKDs contain significant amounts of calcium carbonate (>20%) which could also be used as partial replacement of limestone filler in PC.

Water contaminated due to mining activities is often acidic and can contain high concentrations of dissolved metals. Cement kiln dust (CKD) is a fine-grained, alkaline material that is generated as a by-product of cement production. Its high lime (CaO) content makes it attractive as a substitute for quicklime in the generation of slurries for the treatment of mine water. The first part of this study analyzed six CKD samples for several physical and chemical properties to determine their variability and to compare them to the characterization of a commercial quicklime sample. Neutralization and precipitation experiments using acidic mine water containing high concentrations of zinc and iron determined that all slaked CKD slurries performed comparably to the quicklime slurry in terms of precipitation of soluble metals. The results of this research show that CKD can be effectively used to neutralize mine water and precipitate and remove dissolved metals.

Portland cement-based products are the most commonly used building materials. However, it is well known that the production of OPC not only consumes a significant amount of natural resources and energy but also releases high quantity of carbon dioxide (CO2) to the atmosphere. Purpose of this work is to develop new cementitious material similar to Portland cement-based concrete, which is convenient in terms of energy and is environmental-friendly at once. This work presents preparation, composition and properties of inorganic aluminosilicate polymer, called geopolymer, synthesized from blast furnace slag and fly ash, activated by sodium hydroxide and cement kiln dust. Study of the microstructure was based on SEM-EDX-WDX, TG-DTA-EGA and XRD analysis.

This thesis has determined that using fly ash as a mineral filler in asphalt pavements can help strengthen and reduce asphalt moisture damage. Also, dynamic shear rheometer tests show that these additives have a stiffening effect on asphalt binder. Moisture related damage is considered one of the main causes of asphalt pavement failure. As water infiltrates a layer of asphalt, it slowly strips away asphalt binder, weakening the aggregate/binder bond. This process, combined with the cyclic loading of traffic, can lead to several different types of asphalt failure including rutting, raveling, bleeding, and cracking. For several decades, research has been conducted to find a solution to this problem. Currently in practice, hydrated lime and a variety of amine-based chemicals are being used as anti-stripping agents. However, as an emphasis towards sustainability has increased, waste products are now being investigated for this purpose. This thesis investigated the anti-stripping effectiveness of two waste products: fly ash and cement kiln dust (CKD), and compared them with hydrated lime and an amine-based chemical additive. The results indicate that class C fly ash can be used as an asphalt anti-stripping additive; however it is more costly than lime or amine chemicals.

This diploma thesis is focused on methods of using cement kiln by-pass dust in building materials technology. By-pass dust was treated to remove chlorides and could then be used as other constituent to various types of cements in the amount of 0–5 wt. % according to ČSN EN 197-1. The properties of dusts before and after chloride removal were examined and after incorporating modified by-pass dust into the cement, the properties of fresh and hardened cement pastes and mortars were studied. It was found that modified by-pass dust after incorporation into cement fulfill requirements of ČSN EN 197-1.