Determınatıon Of Mechanıcal Propertıes Of Geopolymer Based Composıtes Suıtable For 3d Addıtıve Manufacturıng

Abstract

The use of traditional concrete for many years until today has brought many problems. The production and use of Portland cement are the most responsible for the problem caused by conventional concrete. It is estimated that the use of concrete will continue to increase as the needs of humanity such as sheltering, and transportation continue. The detrimental influence on the environment of Portland cement so far can be understood by the fact that it accounts for 8-9% of CO2 emissions worldwide. It is obvious that this effect will negatively affect our sustainable future. Therefore, it is necessary to eliminate the production of concrete by offering a new binding material that will meet the needs of humanity with a novel, sustainable and “green” alternative. In addition to the environmental damage caused by concrete produced with Portland cement, the storage and recycling of construction demolition waste in the world are another problem that humanity must deal with. About 1/3 of the total annual waste of the European Union is covered by construction demolition waste. In developed European countries, most of this waste is reused, while in countries that do not have large economies, this rate is quite low. In addition, in European Union countries with large economies, the rate of production of value-added goods by the reuse of construction demolition is very low/limited. These materials are used in transportation projects such as road pavements and filling materials. In addition to materials related issues, traditional production methods used in the construction industry are considered to be very slow, risky and costly in today's technology. Occupational accident risk is of great importance in-molded construction productions used until today. Mold and labor costs are another issues that needs to be optimized during the production stages. Therefore, researchers carried out studies focusing on innovative and sustainable ways in production methods. The aim of this thesis is to develop innovative, sustainable and “green” 3 dimensional (3D) printable geopolymer-based composites developed within the scope of the thesis, to minimize the harmful effect of cement production on the environment, to reuse construction demolition waste with added value, and to expand automation by developing 3D production in the construction industry. In this context, the rheological properties of geopolymer binders suitable for 3D printing were determined. After that, the mixtures suitable for printing were produced by 3D additive manufacturing (AM) and their mechanical properties were determined. The anisotropic behavior and interlayer bond strength properties of the produced mixtures were determined as a result of curing at ambient conditions for 7, 28, 56 and 90 days. As a result, it is believed that the produced geopolymer composites suitable for 3D-AM will bring sustainable solutions to many problems encountered in the construction industry, such as global warming, excess cost, occupational accidents and management of construction demolition wastes.