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Title:	Polyethylene terephthalate (PET) waste incorporating fly ash and nanosilica in concrete exposed to high temperature
Authors:	Ibrahim Hakeem Mohammed (P78443)
Supervisor:	Siti Aminah Osman, Assoc. Prof. Dr.
Keywords:	Universiti Kebangsaan Malaysia -- Dissertations Dissertations, Academic -- Malaysia Concrete mixers Fly ash Polyethylene terephthalate
Issue Date:	14-Mar-2019
Description:	The accumulation of Polyethylene Terephthalate (PET) waste that has resulted from a single use of drinking water bottles, and the fly ash (FA) generated from power stations have become the main phenomenon that threats the environment. Furthermore, the increasing of concrete demand had led to the increase of cement production and significantly increases the pollution through the emission of carbon monoxide (CO). Generally, the normal concrete (NC) and high strength concrete (HSC) suffering from brittleness and weakness in tensile strength, and the HSC suffering of spalling when exposed to high temperatures due to the low porosity. Therefore, this study aims to produce NC that contains the best ratio of PET waste and has the best mechanical properties before and after exposed to different high temperatures (26, 100, 300, 400 and 700°C). In this study, four groups of concretes were tested i.e. NC contains PET; sustainable concrete contains FA with/without PET, HSC contains nano-silica (NS) with/without PET and HSC combined FA, NS and PET. Some of these HSC specimens were exposed to high temperature at 400°C and 700°C as to investigate its behavior. PET of 0.25, 0.75, 1.25 and 1.75% ratios were used as a partial replacement of coarse aggregate weight in NC, whilst 0.25% and 0.75% of PET ratios were used in HSC mixes. Meanwhile for cement weight was replaced by 30, 35, 40% of FA, and NS was added by 2.5, 5 and 7.5% of cement weight to produce sustainable concrete and HSC mixes, respectively. Different tests were conducted to examine the workability, mechanical properties, porosity and the gasses emitted from the concrete mixes. The optimal ratios of PET, FA and NS were then marked. The results exhibited that the ratio 1.25% of PET reduced the slump clearly while improved the mechanical properties of NC contains PET until 300°C. Elevating the temperature above 300°C reduced the mechanical properties for all NC specimens. Combination of HSC specimens with FA and NS reduced the slump slightly, while gave compressive strength of 10% and 42% higher than the control specimens at normal temperature and 400°C, respectively. While the same specimens showed partial spalling after being exposed to 700°C but kept 34% superior than control specimens when exposed to high temperatures. However, the combination of PET with NS and FA in HSC resulting in a significant improvement of 47.5% at 400°C and residual strength 69% higher than control specimens at 700°C as well as no spalling effect. The porosity results suggest that the pore size larger at higher temperature, and the PET does not affect the pore size significantly in NC specimens, and the FA and NS refine the coarse pores significantly where the total porosity is reduced up to 44 %. Finding from this study has shown that the inclusion of low ratios of PET waste in NC and HSC improves the mechanical properties. Presence of PET in HSC prevented spalls at 700°C. Inclusion of 35% FA, 5% NS and 0.25% PET in one mix reduced the required cement 40%. On the other hand, using PET in NC and HSC fired constitutes a direct threat to the human life, especially in closed areas. As the amount of CO gas emitted from burned specimens exceeded tens of times the human limits allowed (9 ppm) to inhalation.,Ph.D.
Pages:	189
Call Number:	TA439.M836 2019 3 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

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