Periodic Reporting for period 2 - CNF (The role of microfibrillated cellulose fibres to tune the rheological behaviour of fibre-cementitious and fibre-clay mixture for 3D printing application)
Reporting period: 2023-06-01 to 2024-05-31
One of the main challenges in the field of 3D printing of cement and concrete is to reach optimum flow behavior of the mixture. In this regard, the water and cement mixture needs to meet the permeability, extrudability, and printability features before 3D printing, while the favorable mechanical strength and low-shrinkage properties are accessible after 3D printing.
In our first publication of the project CNF-101024074, the microfibrillated cellulose (CNF) was produced and mixed with ordinary Portland cement (OPC) in different fiber proportions and water to cement ratio (WCR). The primary goal of this work was aimed to tune the rheological changes of the mixtures due to different parameters such as shear rate and time evolution. The secondary goal was to prepare CNF-OPC composite with different fiber contents and WCR aiming the lightweight cement composite with optimum mechanical properties. The microstructure of obtained CNF-OPC composites studied to observe how the fibers and cement particles was compounded and change the mechanical properties, density, and rheological behaviors.
The second paper entitled as “Selection of suitable cellulose nanofibers derived from eco-friendly sources for the production of lightweight cementitious composites with tuned rheological, mechanical, and microstructure properties”. Based on the state of the art and our previous research, it was elucidated that the bio-based CNF materials need to be into the spotlight as an important alternative due to their availability, sustainability and their effect on density, porosity, fresh property, rheological behavior, and mechanical properties of fiber-cement composite. This experimental research paper has been done to tune and to produce different CNF with different methods from different material resources to obtain CNF-cement composite with a favorable density, fresh property, rheological behavior, and mechanical properties from both scientific and industrial standpoints.
This project was designed to decrease the chemical additives e.g. conventional accelerators, and to increase the proportion of bio-based materials such as wood or cellulose material.
The fellow has planned to increase his interactions in academia/prestigious universities and in intermediate fields to continue his career as an assistant professor and professor. The fellow has this chance to increase his research index by open science data publications that have been prepared by MSCA. The fellow has planned an intensive training plan in Finland and Switzerland for the period of three months and before the outgoing phase. During his stay in Columbia University, as a visiting researcher, the fellow can have access to all the facilities available in Carleton Lab, along with any additional characterization equipment or computing capabilities needed in the School of Engineering and Applied Science (SEAS) at Columbia. The fellow had full-time lab support and the proximity of each of these capabilities within Carleton Lab makes the proposed work seamless from material processing to performance testing.
Due to the primary career plan, the fellow involved in the supervision of two master thesis (one for rheological assessment and the second on hardened state study) and teaching several courses in rheology engineering and processing, which improved the project management competence and communication skills of the fellow in an academic environment. Moreover, the fellow involved in the life and projects of Dr. Perrot research and Dr. Shiho Kawashima's group (BS, MS, PhD students) working on the processing of cement and clay-based materials at University of Bretagne Sud and at Columbia University (Carleton Lab), respectively.
In our first publication of the project CNF-101024074, the microfibrillated cellulose (CNF) was produced and mixed with ordinary Portland cement (OPC) in different fiber proportions and water to cement ratio (WCR). The primary goal of this work was aimed to tune the rheological changes of the mixtures due to different parameters such as shear rate and time evolution. The secondary goal was to prepare CNF-OPC composite with different fiber contents and WCR aiming the lightweight cement composite with optimum mechanical properties. The microstructure of obtained CNF-OPC composites studied to observe how the fibers and cement particles was compounded and change the mechanical properties, density, and rheological behaviors.
The second paper entitled as “Selection of suitable cellulose nanofibers derived from eco-friendly sources for the production of lightweight cementitious composites with tuned rheological, mechanical, and microstructure properties”. Based on the state of the art and our previous research, it was elucidated that the bio-based CNF materials need to be into the spotlight as an important alternative due to their availability, sustainability and their effect on density, porosity, fresh property, rheological behavior, and mechanical properties of fiber-cement composite. This experimental research paper has been done to tune and to produce different CNF with different methods from different material resources to obtain CNF-cement composite with a favorable density, fresh property, rheological behavior, and mechanical properties from both scientific and industrial standpoints.
This project was designed to decrease the chemical additives e.g. conventional accelerators, and to increase the proportion of bio-based materials such as wood or cellulose material.
The fellow has planned to increase his interactions in academia/prestigious universities and in intermediate fields to continue his career as an assistant professor and professor. The fellow has this chance to increase his research index by open science data publications that have been prepared by MSCA. The fellow has planned an intensive training plan in Finland and Switzerland for the period of three months and before the outgoing phase. During his stay in Columbia University, as a visiting researcher, the fellow can have access to all the facilities available in Carleton Lab, along with any additional characterization equipment or computing capabilities needed in the School of Engineering and Applied Science (SEAS) at Columbia. The fellow had full-time lab support and the proximity of each of these capabilities within Carleton Lab makes the proposed work seamless from material processing to performance testing.
Due to the primary career plan, the fellow involved in the supervision of two master thesis (one for rheological assessment and the second on hardened state study) and teaching several courses in rheology engineering and processing, which improved the project management competence and communication skills of the fellow in an academic environment. Moreover, the fellow involved in the life and projects of Dr. Perrot research and Dr. Shiho Kawashima's group (BS, MS, PhD students) working on the processing of cement and clay-based materials at University of Bretagne Sud and at Columbia University (Carleton Lab), respectively.
The CNF amount produced at the secondment institutes to provide the samples and data sets for the first publication entitled “Microfibrillated cellulose as a new approach to developing lightweight cementitious composites: Rheological, Mechanical, and Microstructure Perspectives” (already published) and the second publication entitled as “Selection of suitable cellulose nanofibers derived from eco-friendly sources for the production of lightweight cementitious composites with tuned rheological, mechanical, and microstructure properties” (already published). The manuscripts of third and forth paper are in progress and explained in technical report.
The experimental tests were done as below:
• The CNF was mixed with ordinary Portland cement (OPC) in different fiber proportions and water to cement ratio (WCR) and the samples were prepared/stored for characterization.
• The rheological changes such as steady-state and dynamic tests were done due to different parameters such as shear rate and time evolution.
• The dry density of the samples was measured to find the density of the mixtures containing different contents of CNF and the correlation between density and water to cement ratio.
• The primary results of using CNF with cement showed a remarkable change in density, yield stress, and shrinkage of the CNF-cement mixture.
• Different fiber sources was used to produce the CNF and applied with cement and clay to find out the rheological and fiber election prespective.
• The composites was 3D printed and the printing parameters were studied both for CNF-cement and CNF-clay.
The other activities by now mentioned as below:
• MSCA online webinar (2021)
• 1st RILEM online workshop on measurement technique for fresh properties of printable materials (2021)
• Online workshop “Digital concrete: Dream or reality? New green or ecological monster” (2021)
• 3rd RILEM International Conference, Loughborough, UK (2022)
• V International Conference Progress of Recycling in the Built Environment, Weimar, Germany (2023)
The experimental tests were done as below:
• The CNF was mixed with ordinary Portland cement (OPC) in different fiber proportions and water to cement ratio (WCR) and the samples were prepared/stored for characterization.
• The rheological changes such as steady-state and dynamic tests were done due to different parameters such as shear rate and time evolution.
• The dry density of the samples was measured to find the density of the mixtures containing different contents of CNF and the correlation between density and water to cement ratio.
• The primary results of using CNF with cement showed a remarkable change in density, yield stress, and shrinkage of the CNF-cement mixture.
• Different fiber sources was used to produce the CNF and applied with cement and clay to find out the rheological and fiber election prespective.
• The composites was 3D printed and the printing parameters were studied both for CNF-cement and CNF-clay.
The other activities by now mentioned as below:
• MSCA online webinar (2021)
• 1st RILEM online workshop on measurement technique for fresh properties of printable materials (2021)
• Online workshop “Digital concrete: Dream or reality? New green or ecological monster” (2021)
• 3rd RILEM International Conference, Loughborough, UK (2022)
• V International Conference Progress of Recycling in the Built Environment, Weimar, Germany (2023)
The overall scientific objectives of the fellow were also planned as below:
• Anticipated publications:
3-4 publications had been planned for this project.
By now two publications already published and 2 more manuscripts are in progress.
Paper 1: Comparison of uniformity, rheological and mechanical properties of CNF-cement/CNF-clay composites produced by grinding and microfluidization. Paper 2: Printability index of CNF-cement, printing parameters, and property of 3D printed specimen. Paper 3: The role of different CNF in CNF-cement composite properties and rheological properties of 3D printed specimens. Paper 4: Mechanical properties of a 3D printed specimen of admixture (CNF, cement, and clay) and the printability index.
• Anticipated conference, workshop attendance, courses, and /or seminar presentations:
2-3 conferences had been planned for this project.
Conference 1: Already attended conference: Microfibrillated cellulose as a new approach to tune the rheological behavior of cementitious composite for 3D printing applications. 3rd RILEM International Conference (June 2022, Loughborough, UK).
Conference 2: Already attended conference: V International Conference Progress of Recycling in the Built Environment, Weimar, Germany (2023)
• The fellow has planned to maximize his connection with other pioneer researchers in different institutes and to be involved to discuss some results and collaboration in the EU, UK, and USA. The fellow joined active RILEM technical committees on 3D concrete printing in order to meet leading research groups in the field, build an interesting network of international researchers and participate in interlaboratory testing programs and papers.
• Anticipated publications:
3-4 publications had been planned for this project.
By now two publications already published and 2 more manuscripts are in progress.
Paper 1: Comparison of uniformity, rheological and mechanical properties of CNF-cement/CNF-clay composites produced by grinding and microfluidization. Paper 2: Printability index of CNF-cement, printing parameters, and property of 3D printed specimen. Paper 3: The role of different CNF in CNF-cement composite properties and rheological properties of 3D printed specimens. Paper 4: Mechanical properties of a 3D printed specimen of admixture (CNF, cement, and clay) and the printability index.
• Anticipated conference, workshop attendance, courses, and /or seminar presentations:
2-3 conferences had been planned for this project.
Conference 1: Already attended conference: Microfibrillated cellulose as a new approach to tune the rheological behavior of cementitious composite for 3D printing applications. 3rd RILEM International Conference (June 2022, Loughborough, UK).
Conference 2: Already attended conference: V International Conference Progress of Recycling in the Built Environment, Weimar, Germany (2023)
• The fellow has planned to maximize his connection with other pioneer researchers in different institutes and to be involved to discuss some results and collaboration in the EU, UK, and USA. The fellow joined active RILEM technical committees on 3D concrete printing in order to meet leading research groups in the field, build an interesting network of international researchers and participate in interlaboratory testing programs and papers.