Experimental study of 3D concrete printing with addition of recycled glass cullet aggregates

• Main Author: Yeo, Sherilyn Jing Yi
• Other Authors: Tan Ming Jen
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/150922
• Institution: Nanyang Technological University

Man-made concrete is a popular material used for construction in various countries. The evolution of construction technology has been targeting to reduce manpower and increase rate of construction. This has led to the invention of 3D concrete printing(3DCP) which has several benefits such as freedom in design and fewer manpower needed. This has brought about greater convenience for construction using concrete. However, the increase in usage of concrete has led to several environmental impacts. One of which would be soil erosion due to widespread of sand mining. Sand is a commonly used aggregate in concrete. Therefore, in order to reduce the amount of sand used in concrete, recycled glass is being explored as a possible replacement. Recycled glass is an ideal replacement substance due to it being recyclable while maintaining its properties. It is also beneficial for the environment as there would be lesser glass being disposed in landfills. However, there is still a need to investigate the impacts of recycled glass on the properties on concrete. There have been several studies on the effects of recycled glass on concrete. However, the effects on 3DCP are hardly being studied. The study aims to create an environmentally friendly concrete that is suitable for 3DCP. Therefore, this report will discuss how the effects of recycled glass on concrete will subsequently affect the 3DCP process. The percentage of recycled glass will be varied and the fresh and mechanical properties of the concrete will be studied. Comparisons of mechanical properties of 3D printed and casted samples will also be done. In addition, aspects such as buildability and extrudability of the concrete mixture is crucial during a 3DCP process. An ideal mixture would be one that has maximum buildability while maintaining its extrudability. The second part of this study explores different mix proportions by changing fineness modulus, glass-binder ratio and water-binder ratio to achieve a mixture that has maximum buildability. A limit graph that shows the appropriate proportions for the mixture will be obtained at the end of the study. The report will provide the methodologies used throughout the investigation. At the end of the report, aspects that are lacking in the study will also be discussed. Recommendations for future work on ways to enhance the study on creating a mixture with improved buildability will also be stated.