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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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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.