Geopolymer. Covert Glass and Plastic Bottle Wastes to Green and Energy Efficient Construction Materials

The aims of this project is
1. Convert municipal solid wastes (waste glass and plastic bottles) to energy-efficient and high-quality construction materials;
2. Produce eco-friendly construction materials and solve environmental issues about municipal solid wastes;
3. Develop Geopolymer Non-Autoclaved Aerated Concrete (GNAAC).

What is the problem?
Cement is responsible for 5% of worldwide carbon dioxide (CO2) emissions. To decrease this gas emission, alternative binder material has to be used. For example, Geopolymer, which has a solid potential to replace cement to reduce CO2 emissions. Kazakhstan faces severe problems of disposing of municipal solid wastes including glass and plastic bottles. The city of Astana with a population of about one million inhabitants generates approximately 1,118 tons of waste per day. Most of the municipal solid’s waste (more than 97%) are sent to landfills without recycling. Another challenge in Astana city is the increase in energy demand and consumption due to severe and long winter weather. Nazarbayev University campus is also facing the same problems. Therefore, if the municipal solid wastes are converted to energy-efficient and high-quality construction materials, they can be good and eco-friendly materials.

Proposed solution
This research project aims to develop eco-friendly geopolymer none-autoclaved aerated concrete (GNAAC) made of glass and plastic bottle wastes. It is well known that aerated concrete (AC) is a modern energy-efficient and lightweight construction material made of cementitious materials, silica-rich materials, and expansive component. However, the autoclave curing used for the AC has a potential risk and is environmentally costly because of its high pressure and temperature operation using fossil fuels. The utilization of both glass bottles as aggregates and silica-rich materials and plastic bottles as fibers in manufacturing the GNAAC can provide several synergetic effects: improvement of both compressive and flexural strengths and elimination of the autoclaved curing method. This is also fitted to green building technology for more energy-efficient and environmentally friendly construction practices. 3-dimensional Geopolymeric network that is formed due to rapid dissolution of silico-aluminate reactive materials provides high strength of the material. Thus, proposed project deals with serious issues such as waste recycle management and greenhouse gas emission.

Conclusion:
SLL project has given an opportunity to young group members to test their research ideas and hypophysis. Much obliged to project organizer and sponsors, it was possible to gain experimental test results in short amount of time.
In general, test results were satisfactory and objectives were fulfilled. In the future, the proposed research project might be improved as following:
1. Compressive strength of geopolymer mixture should be increased by adjusting adequate proportion of GGBFS/FA,
2. Extensive literature review should be done for improving mixture proportion.
3. In order to safely gain research aim, the application of proposed project in real life, it is preferable to test tensile strength of the product in the future.