Periodic Reporting for period 1 - TemGPC (Thermal and mechanical behaviours of geopolymer concrete at elevated temperatures)
Berichtszeitraum: 2022-01-01 bis 2023-12-31
Concrete is a non-uniform, multi-phase porous material. With the increase in temperature, the chemical configuration of the material changes, and the mortar and coarse aggregate, owing to their different thermal expansions, will produce different thermal stresses, thereby reducing their bonding strength. The thermal and mechanical behaviours of geopolymer concrete that uses geopolymer to replace traditional Portland cement, are different from those of Portland cement concrete in many ways. In order to enable the widespread and safe use of geopolymer concrete (GPC) in construction industry where fire safety is extremely important, this project carried out a systematic study on the thermal and mechanical behaviours of geopolymer concrete at elevated temperatures. The scientific aim of the project is to study the thermal and mechanical behaviours and corresponding failure mechanism of GPC when it is exposed at various different elevated temperatures. The research objectives include:
(1): To develop the stress-strain-temperature constitutive equations of GPC at various elevated temperatures and investigate the effect of temperature on the thermal and mechanical properties of GPC by means of damage mechanics modelling.
(2): To develop 3-phases (gaseous, liquid, solid) and 3-fields (temperature, mass-concentrations of water and water vapour, displacements) finite element coupled analysis (FECA) model to examine the effect of pore pressure on the thermal and mechanical strains and failure mechanism of GPC.
(3): To develop GPC transient strain models to investigate the effect of pre-load on the thermal strain, mechanical compressive strain, and ultimate compressive strength of GPC at various elevated temperatures.
(4): To provide an analysis model for the prediction of fire resistance of GPC when it is exposed in different fire conditions.
(5): To provide training on conducting steady-state tests, transient-state tests, and fire tests of GPC by the host and transfer knowledge from the ER on the multi-phase/multi-scale numerical modelling of concrete structures from his previous research in leading labs in China.
The study includes the effect of temperature on the thermal and mechanical properties of geopolymer concrete and the combined effect of the initial stress and temperature on the constitutive relation of geopolymer concrete at various different temperatures. The research methodology includes the use of advanced experimental testing techniques and multi-physics and multi-phases computer modelling, and the development of theoretical models based on the results obtained from both the experimental and numerical studies. The research creates new knowledge and improve our understanding on the temperature effect on concrete behaviour and performance. The work helps maintain EU excellence in concrete research. The outcome of the project also leads to the development of new types of concrete with targeted performance. This project covers a wide range of disciplines including materials, chemistry, physics, engineering, and computer science. Through the project the individual fellowship has significantly improved his interdisciplinary knowledge and innovative research skills as well as his career development.
(1): To develop the stress-strain-temperature constitutive equations of GPC at various elevated temperatures and investigate the effect of temperature on the thermal and mechanical properties of GPC by means of damage mechanics modelling.
(2): To develop 3-phases (gaseous, liquid, solid) and 3-fields (temperature, mass-concentrations of water and water vapour, displacements) finite element coupled analysis (FECA) model to examine the effect of pore pressure on the thermal and mechanical strains and failure mechanism of GPC.
(3): To develop GPC transient strain models to investigate the effect of pre-load on the thermal strain, mechanical compressive strain, and ultimate compressive strength of GPC at various elevated temperatures.
(4): To provide an analysis model for the prediction of fire resistance of GPC when it is exposed in different fire conditions.
(5): To provide training on conducting steady-state tests, transient-state tests, and fire tests of GPC by the host and transfer knowledge from the ER on the multi-phase/multi-scale numerical modelling of concrete structures from his previous research in leading labs in China.
The study includes the effect of temperature on the thermal and mechanical properties of geopolymer concrete and the combined effect of the initial stress and temperature on the constitutive relation of geopolymer concrete at various different temperatures. The research methodology includes the use of advanced experimental testing techniques and multi-physics and multi-phases computer modelling, and the development of theoretical models based on the results obtained from both the experimental and numerical studies. The research creates new knowledge and improve our understanding on the temperature effect on concrete behaviour and performance. The work helps maintain EU excellence in concrete research. The outcome of the project also leads to the development of new types of concrete with targeted performance. This project covers a wide range of disciplines including materials, chemistry, physics, engineering, and computer science. Through the project the individual fellowship has significantly improved his interdisciplinary knowledge and innovative research skills as well as his career development.
The objectives of the proposed project have be achieved through five integrated work packages (WPs):
WP1: Steady-state tests of GPC at various elevated temperatures
WP2: Transient-state tests of GPC at various elevated temperatures
WP3: Coupled heat and mass transfer analysis of GPC at elevated temperatures
WP4: Fire tests of small scale GPC specimens
WP5: Multi-physics and multi-phase modelling of GPC in fire
WPs1 and 3 are related to objective 1; WPs2 and 3 are related to objective 3; WPs4 and 5 are related to objectives 2 and 4; Objective 5 is covered by all five WPs.
The project so far has produced three research papers which have been published, two research papers which have been submitted to journal and are in review process, and one is in preparation. All publications, the results and their exploitation and dissemination have been done in line with the European Commission objective of ‘Open Access’ in Research and Innovation in order to optimize the impact of publicly funded scientific research and to enhance the research capabilities of the partnership and Europe’s reputation for scientific excellence.
WP1: Steady-state tests of GPC at various elevated temperatures
WP2: Transient-state tests of GPC at various elevated temperatures
WP3: Coupled heat and mass transfer analysis of GPC at elevated temperatures
WP4: Fire tests of small scale GPC specimens
WP5: Multi-physics and multi-phase modelling of GPC in fire
WPs1 and 3 are related to objective 1; WPs2 and 3 are related to objective 3; WPs4 and 5 are related to objectives 2 and 4; Objective 5 is covered by all five WPs.
The project so far has produced three research papers which have been published, two research papers which have been submitted to journal and are in review process, and one is in preparation. All publications, the results and their exploitation and dissemination have been done in line with the European Commission objective of ‘Open Access’ in Research and Innovation in order to optimize the impact of publicly funded scientific research and to enhance the research capabilities of the partnership and Europe’s reputation for scientific excellence.
This project addresses one of the most challenging problems in concrete materials. The research carried out has created new knowledge and improves our understanding of the fire effect on concrete behaviour and performance. The work helps maintain EU excellence in concrete research. With the help of advanced technology, the material characterisation analysis of heated concrete is of scientific importance and has become popular. The outcome of this kind of analysis can lead to the development of new types of concrete with targeted performance. Moreover, the interdisciplinary nature of the project not only offers a link of research and training in a collaborative academic environment but also bridges the gaps between the fundamental and applied research and between the research in materials and that in structures. Economic and social development places increasing demands on infrastructure throughout the world. Concrete is the most widely used construction material in the world. Fire represents one of the most severe environmental conditions to which structures may be subjected. The development of appropriate fire safety measures for structural materials not only can bring economic benefit but also can save lives. Therefore, apart from its scientific impact, the proposed research also has great social, economic and environmental impacts.