Investigation of the Performance of Polyester and Vinylester Resin Polymer Concrete Composites with Different E-Waste Ratios Under Extreme Conditions
Thesis Type: Postgraduate
Institution Of The Thesis: Erzincan Binali Yildirim University, Fen Bilimleri Enstitüsü, İnşaat Mühendisliği, Turkey
Approval Date: 2024
Thesis Language: Turkish
Student: Ayşegül Diyarbakır
Supervisor: Halit Alperen Bulut
Abstract:
This study is based on the hypothesis that the plastic-origin structure of e-waste shows excellent compatibility with resin and can positively affect the performance of polymer concrete under extreme conditions. For this purpose, e-waste was used in place of quartz aggregate and gravel, which constitute the aggregates of polymer concrete, at rates of 0%, 4%, 8%, 12%, 16%, and 20%. In the study where unsaturated polyester resin and vinyl ester resin were selected as the binder materials for the polymer concretes, the performance of these concretes under extreme conditions (50, 100, 150, 200, 250, and 300 freeze-thaw cycles) and high temperatures (50°C, 100°C, 150°C, and 200°C) was examined in detail. Additionally, the changes in the internal structures of the concretes exposed to extreme conditions were evaluated by performing SEM (scanning electron microscope) analyses of the polymer concretes. The polymer concretes without e-waste were used as control concretes in the experiments. It was observed that the polymer concretes containing polyester resin with different e-waste ratios were the most adversely affected in terms of the freeze-thaw test. The polymer concretes produced with e-waste combined with vinyl ester resin showed superior performance against freeze-thaw cycles. Indeed, after 300 freeze-thaw cycles, the weight losses of the control and e-waste vinyl ester resin polymer concretes were very close to zero, ranging between 0.17% and 0.22%. However, for example, while the compressive strength of PREP8 before the freeze-thaw cycle was 40.45 MPa, the compressive strength after the cycle was lower, at 34.2 MPa. It was determined that vinylester resin showed more adverse behavior compared to polyester regarding weight loss after high temperatures. Additionally, the threshold value for weight loss in polyester resin polymer concretes was 150°C, while this value was 100°C in vinyl ester resin polymer concretes. Overall, it was determined that 150°C was a distinguishing feature in polymer concretes with both types of resin and different e-waste ratios. At this temperature, all polymer concretes showed gains in compressive strength rather than losses. The SEM analysis results were consistent with the data obtained from the high-temperature test. Experimental findings depending on the e-waste ratios (especially 4% and 8%) and resin type confirmed the hypothesis of this study.