Παρασκευή γεωπολυμερών από απόβλητα κατεδαφίσεων και μελέτη της συμπεριφοράς τους

Μπότης, Ορέστης; Botis, Orestis

dc.contributor.author	Μπότης, Ορέστης	el
dc.contributor.author	Botis, Orestis	en
dc.date.accessioned	2022-09-07T06:26:35Z
dc.date.available	2022-09-07T06:26:35Z
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/55606
dc.identifier.uri	http://dx.doi.org/10.26240/heal.ntua.23304
dc.rights	Default License
dc.subject	Γεωπολυμερές	el
dc.subject	Απόβλητα	el
dc.subject	Κατασκευές	el
dc.subject	Σκυρόδεμα	el
dc.subject	Ανακύκλωση	el
dc.subject	Geopolymer	en
dc.subject	Cement	en
dc.subject	Construction	el
dc.subject	Recycling	el
dc.subject	Waste	el
dc.title	Παρασκευή γεωπολυμερών από απόβλητα κατεδαφίσεων και μελέτη της συμπεριφοράς τους	el
heal.type	bachelorThesis
heal.classification	ΜΕΛΕΤΗ ΥΛΙΚΩΝ	el
heal.language	el
heal.access	free
heal.recordProvider	ntua	el
heal.publicationDate	2021-09-27
heal.abstract	In this work an attempt was made to investigate the development of a class of building materials called geopolymers through the alkali activation of demolition waste and the study of the effect of additives on the properties of the final products. Geopolymers are of special interest in the construction field because of their ability to develop superior properties, depending on the raw materials composition and the conditions of the geopolymer reaction. The main advantages of geopolymers compared to the other building materials is the ability to use industrial by-products like fly ash and construction and demolition materials (CDWs) as raw materials, and the requirement for mild temperatures for their production. Thus, sizable energy savings and reduction in CO2 emissions are achieved. Furthermore, reuse of waste products is made possible, which would otherwise end up in landfills or in the environment, and the mining of raw materials is made unnecessary. Geopolymer synthesis is the result of a chemical reaction between an aluminosilicate feedstock and an alkaline activator. In this dissertation was studied the behavior of brick that came from a demolished building. The alkaline activator was made by dissolution in water of solid sodium and potassium hydroxides (ΚΟΗ, ΝαΟΗ) and of hydrous sodium silicate. The additives used were also recycled products that had first been processed appropriately. Specifically, expanded polystyrene derived from insulating panels was used as a density reducing agent, and polyethylene fibers derived from plastic waste was used to improve mechanical properties. Lastly, the aggregates used came from used concrete. After it was fractured, the lightest particles were selected and phase change materials were encapsulated therein. These aggregates were added to improve the energy efficiency of the final product. In the beginning, the raw material was characterized regards its chemical and mineralogical composition, as well as its granulometry. Next came the synthesis of the reference samples, as well as of a series of samples reinforced either with expanded polystyrene 1.5% w/w, polyethylene fibers 2.0% w/w or with aggregates 6.0% w/w. A series of samples containing all of the above additives was also produced. Afterwards the sorptivity and the compressive strength of the samples were measured. Following that, the behavior of the samples in different environments was studied. Specifically different series of samples were exposed to the laboratory environment, the weather conditions, a humidity saturated environment, were immersed in water, and one series were subjected to repeating dry-wet cycles. Finally, the compressive strength of the above samples was measured to ascertain their remaining strength. Through this work it was proved that, geopolymers and lightweight geopolymers from brick waste can be prepared as shown. In addition, construction materials made from brick can develop strengths like those of conventional cement. It has also been found that an easy way to prepare lightweight building materials is the addition of polystyrene, while the fibers derived from waste enhance the cohesiveness of the products. Specifically, the reference samples achieved compressive strength of 38.5 MPa, density of 2.0 g/cm3 and sorptivity of 0.13 mm/min0.5. The samples containing expanded polystyrene achieved compressive strength of 12.1 MPa, density of 1.4 g/cm3 and sorptivity of 0.11 mm/min0.5. The samples containing polyethylene fibers achieved compressive strength of 38.3 MPa, density of 2.0 g/cm3 and sorptivity of 0.12 mm/min0.5. The samples containing aggregates achieved compressive strengths of 28.4 MPa, density of 2.0 g/cm3 and sorptivity of 0.14 mm/min0.5. Finally, the samples containing all of the above additives achieved compressive strengths of 10.0 MPa, density of 1.3 g/cm3 and sorptivity of 0.18 mm/min0.5. The samples exhibiting the best behavior in all conditions, and the superior remaining strength were those containing expanded polystyrene, retaining above 85% of their initial strength in all cases, followed by the samples containing polyethylene fibers.	el
heal.advisorName	Τσιβιλής, Σωτήρης	el
heal.committeeMemberName	Τσιβιλής, Σωτήρης	el
heal.committeeMemberName	Μαγουλάς, Κωνσταντίνος	el
heal.committeeMemberName	Κακάλη, Γλυκερία	el
heal.academicPublisher	Εθνικό Μετσόβιο Πολυτεχνείο. Σχολή Χημικών Μηχανικών. Τομέας Χημικών Επιστημών (I). Εργαστήριο Ανόργανης και Αναλυτικής Χημείας	el
heal.academicPublisherID	ntua
heal.numberOfPages	74 σ.	el
heal.fullTextAvailability	false