In the heart of Beijing, researchers are tackling a problem that’s as old as concrete itself: cracking. Anbing Qiu, a scientist at the University of Science and Technology Beijing, is leading a study that could revolutionize how we pour and cure large-volume concrete structures, with significant implications for the energy sector.
Qiu and his team at the Xiong’an Campus Construction Project Command Center are focusing on the thermal and mechanical stresses that cause concrete to crack during the pouring process. “The hydration heat generated by cement-based materials is substantial,” Qiu explains. “This heat, combined with poor heat transfer and boundary constraints, leads to thermal expansion and contraction, storing large stresses that can cause cracks.”
The team used finite element analysis software to create a three-dimensional numerical model of thermal-mechanical coupling. They simulated the temperature field distribution and crack evolution in large-volume concrete structures under different pouring temperatures. The results were enlightening.
They found that lowering the pouring temperature of concrete can significantly reduce the peak structural temperature and narrow the temperature difference within the structure. This, in turn, helps control the generation and evolution of cracks. “As the pouring temperature decreases, the temperature transition zone between the concrete boundary and the interior becomes less pronounced,” Qiu notes. This is because less heat is transferred from the deep structure to the surface, reducing the heat exchange efficiency between the surface boundary and the air.
For the energy sector, this research could be a game-changer. Large-volume concrete structures are crucial in energy infrastructure, from hydroelectric dams to nuclear power plants. Cracks in these structures can compromise their integrity and durability, leading to costly repairs and potential safety hazards.
By understanding and controlling the thermal-mechanical coupling effects, engineers can pour concrete at optimal temperatures, reducing the risk of cracking and enhancing the longevity of energy infrastructure. This could lead to significant cost savings and improved safety in the energy sector.
Moreover, this research opens the door to further developments. Future studies could explore the effects of different concrete mixes, pouring methods, and curing techniques on crack evolution. Additionally, the use of advanced materials and technologies, such as phase-change materials and smart sensors, could further enhance our ability to control and monitor the curing process.
The study, published in the Journal of Engineering Sciences, provides a solid foundation for these future explorations. As Qiu and his team continue their work, the construction industry watches with anticipation, eager to see how this research will shape the future of concrete technology. The potential benefits for the energy sector are immense, promising a future where concrete structures are stronger, safer, and more durable than ever before.
