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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.

Cement Kiln Dust (CKD) and Micronized Rubber Powder (MRP) offer sustainable solutions for soil stabilization, addressing both environmental and engineering challenges. CKD, a byproduct of cement manufacturing, is rich in pozzolanic materials that can enhance clayey soil properties by reducing plasticity and increasing strength. This makes CKD a valuable additive for improving the load-bearing capacity and durability of clayey soils used in construction. MRP, derived from end-of-life tires, contributes to sustainability by recycling waste rubber and adding ductility to treated soils. The incorporation of rubber waste not only helps in reducing the environmental burden of tire disposal but also enhances the flexibility and resilience of the stabilized clayey soil. Utilizing these industrial by-products in soil stabilization not only mitigates waste disposal issues but also promotes the development of resilient and eco-friendly construction materials, making them highly beneficial for sustainable infrastructure projects.The present study investigates the effects of various mix proportions of CKD and MRP on Carbondale soil, a high plastic clay. The soil was stabilized with CKD in proportions of 7%, 14%, and 21%, and MRP in proportions of 0%, 2.5%, 5%, and 10% of the dry unit weight of clayey soil. Comprehensive laboratory tests were conducted, including particle size distribution, Atterberg limits, compaction characteristics using the miniature Proctor, unconfined compressive strength (UCS), ultrasonic pulse velocity (UPV), and resilient modulus (RM). The RM test assessed the soil's elasticity under repeated loading, simulating traffic conditions to evaluate the material's performance in pavement design. These tests aimed to determine the optimal mix proportions that would provide the best combination of strength, stiffness, and durability for use in various geotechnical applications. Results from different tests showed that the addition of MRP significantly altered the properties of the CKD-stabilized soil mix. The miniature Proctor test revealed that the addition of MRP reduced the maximum dry density (MDD) of the mix and slightly increased the optimum moisture content (OMC) of the soil mix, indicating a change in compaction characteristics. From the UCS test, it was observed that while the addition of 2.5% MRP to the CKD soil mix reduced the overall strength, it absorbed considerable amount of strain. Specifically, for soil mixed with 7% CKD, the inclusion of 2.5% MRP absorbed over 60% more strain, despite a 50% reduction in strength. Similarly, the mix with 21% CKD and 2.5% MRP showed a 30% increase in peak strain with a strength reduction of up to 40%. The resilient modulus values indicated that the addition of MRP to the soil mix resulted in strain softening, leading to decreased RM values. The soil mix with 7% CKD and 2.5% MRP showed almost no gain in RM values across all curing periods due to strain softening effects. However, the regression analysis between predicted and experimental RM values showed a positive correlation, with a coefficient of determination (R2) ranging from 0.7 to 0.96, indicating a reliable predictive model for RM based on the tested parameters. These findings highlight the trade-offs between strength and stiffness in CKD and MRP-stabilized soils, offering insights for optimizing soil stabilization techniques in sustainable construction practices

Waste generation is a constant activity of daily life, encompassing a wide variety including municipal, hazardous, industrial, agricultural, medical, radioactive, and mining waste, as well as sewage sludge. The purpose of this study is to concentrate on utilizing industrial waste, which adversely affects our environment, for use in engineering construction projects. This aims to evaluate the enhancement in both the soil’s index and engineering properties. In most civil engineering projects, the underlying soils are often unsuitable for construction purposes. Some of these soils experience significant volume changes due to moisture variations, leading to damage and instability of structures and infrastructure built on them. The complete removal and replacement of such high plastic clay and expansive soils is not always a cost-effective solution. Therefore, there's a pressing need to improve their utility by stabilizing them through eco-friendly and sustainable methods.The present research employs five industrial waste materials to enhance the clayey soil available in Carbondale, Illinois. These waste materials include Lime Sludge (LS), Lime Kiln Dust (LKD), Fly Ash (FA), Ground Granulated Blast Furnace Slag (GGBS), and Cement Kiln Dust (CKD). Lime Sludge and Lime Kiln Dust were mixed with the soil at proportions of 2%, 4%, 6%, and 8%. In contrast, Fly Ash and Cement Kiln Dust were used at higher ratios of 8%, 16%, 24%, and 32%. Lastly, Ground Granulated Blast Furnace Slag was added at levels of 5%, 10%, 15%, and 20%, all based on the soil's dry unit weight. The samples were prepared for Unconfined Compression Strength (UCS) and Resilient Modulus (RM) based on the Optimum Moisture Content (OMC) and Maximum Dry Density (MDD) data obtained from miniature Proctor test. These specimens underwent a 14-day curing period, sealed in plastic film and Ziploc bags, and were stored in a controlled water tub at room temperature. The UCS value for the untreated Carbondale soil was 320 kN/m2. The results indicated that with higher content of Lime Kiln Dust (LKD) and Cement Kiln Dust (CKD), the UCS strength tends to increase with CKD exhibiting the most desirable strength characteristics. The UCS value for 8% LKD was 1377.70 kN/m2 i.e., 330.52% increase. While the UCS improvements for 5% GGBS is 51.32% and 6% Lime Sludge (LS) is 51.65% with no significant enhancements, these waste materials can be more effective as modifiers. Furthermore, the study revealed that the optimal quantity of Class F fly ash for soil stabilization is 8% by dry unit weight with UCS value of 486.46 kN/m2 resulting in 52.01% increase in UCS strength, exceeding this percentage might cause reduction in strength. The highest UCS strength was obtained with 24% CKD at 3263.14 kN/m2 which corresponds to 919.70% increase when compared to the untreated soil. The results of the Resilient Modulus (RM or Mr) test indicate that the incorporation of additives to untreated Carbondale soil significantly improved its stiffness characteristics and resistance to different load cycles on the subgrade. However, the soil treated with GGBS showed a decrease in stiffness. The Resilient Modulus values ranged from 2% to 70% for LS, 47% to 128% for LKD, 4% to 35% for FA, 90% to 243% for CKD, and -16% to 0.3% for GGBS for different confining pressures. The regression analysis, using the Uzan (1985) model, showed R² values of 0.910, 0.838, 0.803, 0.871, 0.773, and 0.809 for Carbondale soil, Carbondale soil mixed with 6% LS, 8% LKD, 8% FA, 5% GGBS, and 24% CKD, respectively. These results confirm the reliability of the test, as all samples except the GGBS-treated one have R² values greater than 0.800. Additionally, consolidation tests were conducted to assess the compressibility characteristics of the additives in the soil. The selected samples were those with the mix proportions that yielded the highest UCS strength for each additive. These samples were meticulously prepared based on the moisture-density relationship obtained from the miniature Proctor test and were subjected to loading and unloading in a specific sequence. The results indicated an increase in the Compression Index (Cc) for mixtures with LS, LKD, FA, and CKD. Conversely, the mix containing GGBS displayed a reduction in the Compression Index (Cc). The Carbondale soil stabilized with 6% LS can be used for subbase stabilization as the UCS strength is greater than 345 kPa. Also, 2 to 8% LKD content can be used for subbase and base course stabilization. 8% FA without any activator can be used for subbase stabilizer. GGBS can be used for subbase soil stabilization and finally CKD can be used for both subbase and base course stabilization.

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.

The thesis deals with the study and the characterization of bypass dusts from the cement plants. The aim of the thesis is to search for the possibilities of the usage of that secondary product by means of the cement production. The thesis focuses mainly on the determination of the amount of soluble substances in the dusts, the dependence of dissolution of the soluble share on water – dust ratio, the dependence of dissolution time on the yield of the soluble share and the influence of the temperature on the yield. The physical and chemical properties of the investigated samples taken from several cement plants in the Czech Republic and Slovakia were found out by using the following methods: by TG/DTA analysis, particles size by laser diffraction, phase composition of raw materials, treated raw materials and evaporation residues by X-ray diffraction. It was further investigated whether there was a link between finesse of the particles and the content of soluble substances (chlorides). This was accomplished by classification of the bypass dusts as fine and coarse fraction on the air cassifier with the target parameter X50 1 m. The aim of the classification was to find out whether some of the fractions carry majority share of some of components.