EFFECT OF ALTERNATIVE FUELS ON THE MICROSTRUCTURE AND STRENGTH DEVELOPMENT OF CEMENT
Sorour Semsari Parapari
Materials Science and Engineering, MSc. Thesis Defense, 2015
Thesis Jury
Prof. Dr. Mehmet Ali Gülgün (Thesis Advisor)
Assoc. Prof. Melih Papila (Co-Advisor)
Assoc. Prof. Cleva Ow-Yang
Asst. Prof. Zeynep Başaran Bundur
Assoc. Prof. Burç Mısırlıoğlu
Date &Time: July 29th, 2015 – 11:00 AM
Place: FENS 2019
Keywords : Cement, Alternative Fuels, Phase distribution, Strength development
Abstract
The object of this study was to investigate the effect of using alternative fuels in the cement production process on the microstructure and strength development of the output cement. Five different samples were produced using different alternative fuels in a cement kiln. The samples were prepared respectively with all kinds of alternative fuels (in the dirty kiln), petrocoke (in the clean kiln), plastic waste, a mixture of plastic waste and sewage sludge and lastly sewage sludge.
The microstructure of the cement clinkers was studied with scanning electron microscopy (SEM). The results showed that the distribution of main phases of alite, belite, aluminate and ferrite in the samples prepared with different fuels varies for each of them. The alite/belite ratio varied between 5.2 and 1.5 among the samples. The phase distribution measurements using x-ray diffractometry (XRD) showed good agreement with the SEM results. Chemical composition of the clinkers was analyzed using energy dispersive x-ray spectroscopy and x-ray fluorescence methods. The sulfur and phosphorous amounts were high for some samples.
Hydration experiments were carried out with water to cement ratio of 0.3 and 0.5 by mass. The strength of the hydrated cement samples was measured in the compression tests for several curing ages up to 28 days. Results showed that the compressive strength development of the cement is not affected very much by alternative fuels, except for the sample prepared at the dirty kiln, which showed the lowest values. SEM and XRD analysis results showed the high reactivity of main phases.