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Effect of Surface Hydrophobization on the Durability of Concrete with Cement Kiln Dust

Grzegorczyk-Frańczak Małgorzata, Andrzejuk Wojciech, Hunek Robert, Łagód Grzegorz

Advances in Science and Technology. Research Journal

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2024

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Vol. 18, no 3

214--233

EN

The examinations of concrete involved partial substitution of cement with Cement Kiln Dust (CKD - 0, 5, 10, 20 and 30%). The water/cement (w/c) ratio amounted to 0.36. The obtained findings pertaining to open porosity, density, and volumetric density were found to correlate with the capillary action and absorptivity of the analyzed types of concrete. With the maximum addition of CKD, i.e. 30%, open porosity decreased by 35%. In turn, CKD added in the amount of 5% resulted in a slightly reduced addition compressive strength, amounting to 1.3% and 2.1% following 28 days and 56 days of concrete curing, respectively. After 28 days, the differences in strength were greater when the additive was supplied in higher amounts, i.e. 10%, 20%, and 30%, resulting in 6.5%, 13.4%, and 22.9% decrease, respectively, in spite of strength improvement. In terms of flexural and splitting tensile strengths, comparable relations were noted. As far as the frost resistance test results are concerned, the mass losses in all examined concretes were not significant, reaching up to 0.5%. The strength reduction in the case of the first three series of concretes was below 3%. When the CKD addition was increased to 20% and 30%, the value of the dynamic modulus of elasticity Ec,s decreased to a greater degree, by 8.0% and 14.7%, respectively. The hydrophobization effect is best seen in CKD-free concrete. After the impregnation, the loss of mass following the frost test of the samples is reduced by half. With a higher CKD content, the hydrophobization effectiveness is insignificant. The most favourable results were observed for hydrophobization with the oligomer-based preparation A1.

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Theoretical models to evaluate the effect of SiO2 and CaO contents on the long‑term compressive strength of cement mortar modified with cement kiln dust (CKD)

Abdalla Aso A., Salih Mohammed Ahmed

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 3

art. no. e105

EN

Cement kiln dust (CKD) is a fine powder similar to Portland cement in appearance and produced during grinding and burning of the raw material in the cement kiln. Large amounts of CKD have accumulated in the cement factories annually. It is necessary to re-use this waste material in the construction field instead of landfilling, causing environmental problems, such as the death of vegetation and groundwater pollution. One of the choices to re-use CKD is replacing Portland cement in cement-based mortar and reducing greenhouse gas emissions like carbon dioxide to the atmosphere. This study evaluated the effect of the main two components of CKD, such as SiO2 and CaO, on the long-term compressive strength of cement-based mortar up to 360 days of curing. For that purpose, 167 data of cement-based mortar samples modified with CKD were collected from literature and analyzed. Water-to-binder ratio (w/b) was ranged from 0.34 to 0.76, CKD content ranged from 0 to 50% (dry weight of cement), different CaO and SiO2 of CKD and cement are ranged from 17.64 to 25.45%, and 51.45 to 65.57%, respectively. Several soft computing models, such as multi-expression programming (MEP), artificial neural network (ANN), nonlinear regression (NLR), and full quadratic (FQ), were developed to predict the compressive strength of the cement mortar modified with CKD. Statistical assessment tools were also used to evaluate the proposed models. It was obtained from the modeling results that are increasing SiO2(%) increased the compressive strength of the mortar, and increasing CaO (%) decreased compressive strength for CKD content from 0 to 15% and increasing compressive strength for CKD content of 15-50%. According to the assessment criteria, the ANN model predicted compressive strength up to 360 days of curing better than other developed models with high R2 and a20-index and low RMSE, MAE, SI, and OBJ. The second-best model was the MEP model. Based on the sensitivity analysis, the curing time is the most influential parameter in compressive strength prediction of cement-based mortar modified with CKD.

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The development of an ecofriendly binder containing high volume of cement replacement by incorporating two by-product materials for the use in soil stabilization

Jafer Hassnen, Jawad Ibtehaj, Majeed Zaid, Shubbar Ali

Przegląd Naukowy Inżynieria i Kształtowanie Środowiska

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2021

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Vol. 30, No. 1

62--74

EN

The development of an ecofriendly binder containing high volume of cement replacement by incorporating two waste materials for the use in soil stabilization. This paper investigates the possibility of replacing ordinary Portland cement (OPC) by two waste and by-product materials for the use of a silty clay soil stabilization purpose. The soil was treated by 9.0% OPC where this mixture was used as a reference for all tests. Two by-product materials: ground granulated blast furnace slag and cement kiln dust were used as replacement materials. Consistency limits, compaction and unconfined compression strength (UCS) tests were conducted. Scanning electron microscopy (SEM) analysis was carried out for the proposed binder to investigate the reaction of products over curing time. Seven curing periods were adopted for all mixtures; 1, 3, 7, 14, 28, 52, and 90 days. The results showed that the strength development over curing periods after cement replacement up to 45–60% was closed to those of the reference specimens. The microphotographs of SEM analysis showed that the formation of Ettringite and Portladite as well as to calcium silicate hydrate gel was obvious at curing periods longer than 7 days reflected that the replacing materials succeed to produce the main products necessary for binder formation.

4

Improvement of a subgrade soil by using EarthZyme and cement kiln dust waste

Abdulkareem Ahmed Hazim, Eyada Saadoon O., Mahmood Nabeel S.

Archives of Civil Engineering

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2021

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Vol. 67, nr 2

525--536

EN

Soil stabilization techniques are widely used for road construction to improve the properties of the subgrade materials. Using new additives and stabilizers to improve soil properties can reduce the costs of construction and reduce the possible negative effects of these materials on the environment. The purpose of this study was to evaluate the use of a liquid based nano-material called EarthZyme (EZ) and cement kiln dust (CKD) as admixtures to improve the soil properties. A mixture of two soils was used in this study which were prepared from mixing sand soil and fine-grained soil. Compaction tests were performed on the soil that was stabilized with the CKD to determine the density-water content relationships. Unconfined compression tests were also conducted on specimens without treatment, specimen treated with the CKD only, and specimens treated with the CKD and the EZ after curing period for seven days. The obtained results indicated that adding the CKD to the soil decreased the values of the unconfined compression strength (UCS) from 5 to 15 percent. However, adding the CKD reduced the maximum dry density (MDD) from 10 to 12 %. As discussed herein, soil stabilization with the EZ had insignificant effects on the results obtained from the unconfined compression test.

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Evaluation of different binder combinations of cement, slag and ckd for s/s treatment of tbt contaminated sediments

Lindh Per, Lemenkova Polina

Acta Mechanica et Automatica

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2021

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Vol. 15, no. 4

236--248

EN

The seabed in the ports needs to be regularly cleaned from the marine sediments for safe navigation. Sediments contaminated by tributyltin (TBT) are environmentally harmful and require treatment before recycling. Treatment methods include leaching, stabilisation and solidification to remove toxic chemicals from the sediments and improve their strength for reuse in the construction works. This study evaluated the effects of adding three different binder components (cement, cement kiln dust (CKD) and slag) to treat sediment samples collected in the port of Gothenburg. The goal of this study is to assess the leaching of TBT from the dredged marine sediments contaminated by TBT. The various methods employed for the treatment of sediments include the application of varied ratios of binders. The project has been performed by the Swedish Geotechnical Institute (SGI) on behalf of the Cementa (HeidelbergCement Group) and Cowi Consulting Group, within the framework of the Arendal project. An experiment has been designed to evaluate the effects of adding CKD while reducing cement and slag for sediment treatment. Methods that have been adopted include laboratory processing of samples for leaching using different binder combinations, followed by statistical data processing and graphical plotting. The results of the experiment on leaching of TBT for all samples are tested with a varied ratio of cement, slag, CKD and water. Specimens with added binders 'cement/CKD' have demonstrated higher leaching compared to the ratio 'cement/slag/CKD' and 'cement/slag'. The 'CKD/slag' ratio has presented the best results followed by the ‘cement/slag/CKD’, and can be used as an effective method of s/s treatment of the sediments. The results have shown that the replacement of cement and slag by CKD is effective at TBT leaching for the treatment of toxic marine sediments contaminated by TBT.

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Recycling of cement kiln dust from cement plants to improve mechanical properties of road pavement base course

Ghrair Ayoup M., Louzi Nawal

Roads and Bridges - Drogi i Mosty

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2020

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Vol. 19, no. 3

199--210

EN

In the study, the potential of reuse of cement kiln dust (CKD) to improve the stability properties of the base course of road pavements was investigated. CKD was characterized chemically and physically. The results revealed that addition of CKD improved the mechanical properties of the base course significantly. The results showed a significant increase in California Bearing Ratio, from 234.5% measured for untreated base to 334.4%, 362.7% and 384.6% for CKD content of 5%, 15% and 25%, respectively. In terms of chemical composition, CKD is similar to cement. Scanning electron microscope images showed that the average particle size is approximately 0.5 microns. The granules are mainly spherically shaped, with cubic crystals of sodium and potassium salts. The leachability study of CKD in the base course revealed that heavy metal concentrations in CKD are fixed and insoluble in water.

PL

Przedmiotem badań była ocena możliwości wykorzystania pyłów z pieców cementowych (ang. cement kiln dust, CKD) do poprawy parametrów mechanicznych podbudów drogowych. Pył CKD został scharakteryzowany pod względem właściwości fizycznych i chemicznych. Wyniki badań pozwoliły stwierdzić znaczący pozytywny wpływ dodatku pyłu CKD na właściwości mechaniczne podbudowy. Dodatek pyłu CKD spowodował istotny wzrost wartości wskaźnika nośności CBR. Otrzymano odpowiednio wartości wskaźnika 334,4%, 362,7% oraz 384,6% w przypadku dodatku 5%, 15% i 25% pyłu CKD oraz 234,5% w przypadku mieszanki bez dodatku pyłu. Skład chemiczny pyłu CKD okazał się być zbliżony do składu cementu. Średnia wielkość cząstek, ustalona na podstawie analizy obrazów z mikroskopu elektronowego wynosiła około 0,5 µm. Ziarna miały w przeważającej większości kształt sferyczny z udziałem sześciennych kryształów soli sodu i potasu. Na podstawie badania wymywalności metali ciężkich zawartych w pyłach CKD stwierdzono stałość ich stężeń i nierozpuszczalność w wodzie.

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Compressive strength of selected fine grained soils treated with cement kiln dust and calcareous fly ash

Knapik-Jajkiewicz Karolina, Gaj Grzegorz, Kowalski Adrian, Prędka Edyta

Architecture Civil Engineering Environment

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2020

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Vol. 13, no. 1

79--86

EN

This paper presents the results of unconfined compressive strength tests carried out on samples of two different fine grained soils mixed with anthropogenic materials produced in Poland, showing binding properties - cement kiln dust and fly ash obtained from combustion of brown coal in a pulverized boiler. The tests were performed on cylindrical samples in a testing machine for compression tests after various curing time ranging from 1 to 8 weeks. The conducted work constitutes the first stage of research devoted to the recognition of the effects of calcareous fly ash and cement kiln dust addition into the fine grained soils.

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Chemical characteristics of dust from cement kilns

Uliasz-Bocheńczyk Alicja

Gospodarka Surowcami Mineralnymi

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2019

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T. 35, z. 2

87--102

EN

The cement production process is associated with the emission of dust. These are mainly CKD (cement kiln dust) and BPD (by-pass dust), classified as wastes from group 10 – Wastes from thermal processes, subgroups 10 and 13 – wastes from manufacture of cement, lime and plaster and articles and products made from them. Cement kiln dust is a waste of variable composition and properties, which makes it a difficult material to recover. The main directions of recovery presented in the world literature indicate the use of dust from cement kilns in cement, mortar and concrete production, the production of bricks and in order to improve soil quality and wastewater treatment. Factors affecting chemical and phase compositions of dust from cement kilns are the reason why each waste should be analyzed individually. The paper presents the results of the analysis of the cement kiln dust after dedusting cement kilns and two bypass dusts. Analysis of the chemical composition has shown significant concentrations of chlorine, potassium and calcium in all wastes. The content of: Si, S, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Pb, and Bi has also been confirmed. The analyzed dusts were characterized by the presence of carbonates (calcite, dolomite, and arcanite), quartz, alite, belite, sylvine, anhydrite, and portlandite in their phase composition. The leachates which were characterized by an alkaline reaction. In terms of leachability, high concentrations of chlorine ions in the analyzed dust leachates were confirmed, which significantly limits their use.

PL

Proces produkcji cementu związany jest z emisją pyłów. Są to przede wszystkim pyły z instalacji pieców cementowych (CKD i BDP) klasyfikowane w grupie 10 – Odpady z procesów termicznych, podgrupy 10 13 – Odpady z produkcji spoiw mineralnych (w tym cementu, wapna i tynku) oraz z wytworzonych z nich wyrobów. Pyły z pieców cementowych są odpadem o zróżnicowanym składzie i właściwościach, co powoduje, że są materiałem trudnym do odzysku. Badania przedstawione w literaturze światowej jako główne kierunki odzysku wskazują wykorzystanie pyłów z instalacji pieców cementowych w procesie produkcji cementu, zapraw, betonów; do poprawy jakości gleb i oczyszczania ścieków. Czynniki wpływające na składy chemiczne i fazowe pyłów z instalacji pieców cementowych powodują, że każdy odpad należy analizować indywidualnie. W artykule przedstawiono wyniki badań pyłu z odpylania z instalacji pieca cementowego oraz 2 pyłów z bypassów. Analiza składu chemicznego wykazała znaczącą zawartość: Cl, K, Ca we wszystkich odpadach. Stwierdzono również obecność: Si, S, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Zr, Pb, Bi. Analizowane pyły charakteryzowały się obecnością w składzie fazowym: węglanów (kalcytu, dolomitu, arkanitu), kwarcu, alitu, belitu, sylwinu, anhydrytu i portlandytu. W zakresie wymywalności stwierdzono wysokie stężenia jonów chloru w odciekach z analizowanych pyłów, co znacząco ogranicza możliwości ich wykorzystania.

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Możliwości wykorzystania surowców odpadowych przemysłu cementowego i przetwórstwa mineralnego do produkcji materiałów szklistych i szklano-krystalicznych. Cz.1 – Materiały szklano-krystaliczne na bazie odpadowego pyłu cementowego i perlitu

Zawiła J., Rybicka-Łada J.

Prace Instytutu Ceramiki i Materiałów Budowlanych

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2015

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R. 8, nr 21

76--90

PL

W artykule omówiono możliwości uzyskania materiałów szklano-krystalicznych na bazie odpadowego pyłu cementowego i perlitu. Biorąc pod uwagę ich skład chemiczny, zaprojektowano materiały z układu SiO2-CaO-MgO-Al2O3, uzupełnieniając skład surowcowy o dodatkowy surowiec pochodzenia mineralnego będący źródłem MgO. Zaprezentowano ich składy chemiczne i warunki obróbki termicznej. Materiały szklano-krystaliczne otrzymywano prowadząc kontrolowaną krystalizację szkieł w zakresie temperatury 950–1050°C bez stosowania dodatkowych nukleatorów krystalizacji oraz z ich udziałem w postaci tlenków Cr2O3, Fe2O3 i TiO2. Analiza składu fazowego XRD w pełni potwierdziła szklano-krystaliczny charakter uzyskanych materiałów. Wyniki badań pokazały, że głównymi fazami krystalicznymi analizowanych materiałów po ich obróbce w temperaturze 1000–1050°C i w czasie 180–300 minut są: diopsyd, anortyt i wolastonit, a ich udział zależy od składu wyjściowego. Opracowane w warunkach laboratoryjnych materiały szklano-krystaliczne na bazie pyłu cementowego i perlitu wykazują zdecydowanie większą twardość aniżeli szkło, z którego powstały w wyniku obróbki termicznej. Odznaczają się te materiały równomierną, krystaliczną strukturą i zróżnicowaną kolorystyką, mogą więc znaleźć różnorakie zastosowanie, np. jako materiały okładzinowe – ścienne i podłogowe, do wyrobu różnego rodzaju blatów, płyt itp.

EN

The paper discusses the possibility of obtaining a glass-crystalline materials based on cement kiln dust waste and perlite. Considering their chemical composition, SiO2-CaO-MgO-Al2O3 based materials were designed, supplementing raw material composition by additional mineral component containing MgO. Their chemical compositions and thermal treatment conditions were presented. Glass-ceramic materials were prepared by the controlled crystallization of glass in the temperature range of 950–1050˚C without applying additional nucleating agent of crystallization and their involvement in the form of oxides Cr2O3, Fe2O3 and TiO2. XRD analysis of the phase composition fully confirmed the glass-crystalline nature of the obtained materials. They showed that the major crystalline phases of the analysed material after heat treatment at a temperature of 1000–1050°C and at the time of 180–300 minutes are diopside, anorthite and wollastonite, and their contribution depends on the composition of the starting material. Developed in the laboratory conditions glass-ceramic materials based on cement kiln dust and perlite have much greater hardness than the glass from which they originated as a result of thermal treatment. They are characterized by a uniform crystalline structure and diversified colour schemes. These materials may find various application, for example as wall and floor cladding materials, variety of countertops, slabs, etc.

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Disinfection of sludge from municipal sewage treatment plants with parallel immobilization of heavy metals

Zdenkowski J. A., Słomkiewicz P. M.

Polish Journal of Chemical Technology

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2001

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Vol. 3, nr 3

33-35

EN

The increasing quantity of municipal and industrial sewage is a growing menace to water-soil systems. This paper describes a method of disinfections of municipal wastewater treatment plant sludge with parallel immobilization of heavy metals. A special concern was devoted to immobilizing heavy metals in prepared organic-mineral manure. The main source of heavy metals is industrial sewage mixed with municipal sewage. The application of detritus basalt, which contains aluminosilicates connected with iron (di-and trivalent), calcium and magnesium and which places the function of natural sorbent and ion exchange material having strong relation to heavy metals has produced good results.