Time gap effect on bond strength of 3D-printed concrete

ABSTRACT

An advancing technology that combines the concrete extrusion with a motion control to create structures with complex geometrical shapes without the need for formwork is known as 3D concrete printing. Since this technique prints layer by layer, the time taken to reach the same position in the subsequent layer is important as it will create an anisotropic property that has a weaker tensile strength at the bond interface of the two printed filaments. Through rheological measurement, which reveals the material deformation and flow behaviour, it is possible to examine the material structural build-up due to time-gap effect by measuring at different time delay. This paper focuses on investigating the time-gap effect on the printed filament with rheological and observation at macroscopic-scale to understand the material behaviour of the initial and subsequent printed layer during its fresh phase. Rheological experiment findings reveal that the tensile strength of the printed specimen is correlated to the material modulus at the initial layer.

KEYWORDS:

• 3D concrete printing
• additive manufacturing
• rheology
• time-gap
• tensile bond strength

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes on contributors

Yi Wei Daniel Tay obtained his bachelor’s degree in Mechanical Engineering from Nanyang Technological University in June 2014. He is currently pursuing his PhD in School of MAE, under the supervision of Associate Professor Tan Ming Jen and co-supervisor Associate Professor Leong Kah Fai. His current research interest includes rheology for shear-thinning materials and 3D concrete printing.

Guan Heng Andrew Ting obtained his bachelor's degree in Mechanical Engineering from Nanyang Technological University in 2017. He is currently pursuing his Ph.D. under the supervision of Assoc Professor Tan Ming Jen at the School of Mechanical and Aerospace Engineering at Nanyang Technological University (NTU), Singapore. His current research works focus on the development of printable recycled-glass composite material for additive manufacturing process.

Dr Ye Qian received his bachelor’s degree at Huazhong University of Science and Technology, China, his M.Sc. degrees from Hokkaido University, Japan, and his Ph.D from Columbia University, USA. He is currently a research fellow in NTU assisting Associate Professor Tan Ming Jen to oversee the Building and Construction (B&C) additive manufacturing program. His current research interest is on the rheology of composite materials and 3D concrete printing.

Mr Biranchi Panda received his Master’s degree in Mechanical Engineering from Technical university of Lisbon (collaboration with National Institute of Technology, Rourkela, India) in 2015. Now he is pursuing his Ph.D. under the supervision of Assoc Professor Tan Ming Jen at the School of Mechanical and Aerospace Engineering at Nanyang Technological University (NTU), Singapore. His current research works focus on development of green construction material for additive manufacturing process.

Mr Lewei He received his bachelor’s degree in Mechanical Engineering from Shanghai Jiao Tong University in 2015. He is currently pursuing his Ph.D. under the supervision of Associate Professor Tegoeh Tjahjowidodo at the School of Mechanical and Aerospace Engineering at Nanyang Technological University (NTU), Singapore. His current research works focus on the development innovative nozzles for additive manufacturing process.

Dr Ming Jen Tan attended Anglo-Chinese School and Anglo-Chinese Junior College, Singapore and received both his B.Sc (Eng.) and Ph.D. from The Royal School of Mines, Imperial College, London. He was Japan Society for the Promotion of Science (JSPS) Fellow at Kyoto University in 1991, Science & Technology Agency (STA) Fellow at the Mechanical Engineering Laboratory (A.I.S.T., M.I.T.I.), Tsukuba, Japan 1992–93, Visiting Scientist at Columbia University (2003) and Fulbright Scholar (2004) at both The Anderson School (UCLA) and Kellogg School of Management (Northwestern University) in the United States of America.

Dr Tan has more than 110 publications in various international journals and also has more than 100 publications in international conference proceedings and book chapters. His research has over 1200 citations on a search of 94 research papers (Source: Scopus, as of 1st May 2010). To date, he has attracted over S$2 million research and development funds from various government funding agencies, industries and international sources as Principle Investigator, and over S$6 million including as a collaborator. He has been consulted regularly by local industries for solving material problems and providing solutions.

He is currently Director of the M.Sc. (Mechanics and Processing of Materials) Programme. He is also the Deputy Editor-in-Chief of the International Journal of Computational Materials Science & Surface Engineering, and Archives of Materials Science and Engineering, and on the Editorial Board of the Journal of Achievements in Materials and Manufacturing Engineering.

ORCID

Yi Wei Daniel Tay http://orcid.org/0000-0002-7369-2138

Additional information

Funding

The authors would like to acknowledge Sembcorp Design & Construction Pte Ltd and National Research Foundation (NRF), Singapore for funding and support in this research project.