Profile
Miao Changwen, Academician of the Chinese Academy of Engineering and Professor at Southeast University. He has long been engaged in theoretical research on civil engineering materials and research on engineering technology applications, and has been active on the front lines of China's major engineering construction projects for many years. He has undertaken more than 30 national and provincial/ministerial-level research projects, and has achieved numerous results in research on key technologies for concrete crack resistance, research on technologies for extending the service life and improving the durability of major infrastructure projects, and the development of multifunctional civil engineering materials.
The photo shows the Three Gorges Dam. (Photo by Zheng Jiayu, Xinhua News Agency)
Recently, with the approval of the naming committee of the International Astronomical Union's Minor Planet Center, asteroid No. 578168, discovered by the Purple Mountain Observatory of the Chinese Academy of Sciences, was officially named after Miao Changwen. Another "star of science and technology" shines in the sky.
Miao Changwen is a renowned building materials expert, Academician of the Chinese Academy of Engineering, and Professor at Southeast University. He has devoted more than 30 years to the field of concrete research. He has led his team to participate in the construction of numerous projects, including the Three Gorges Dam on the Yangtze River, the Beijing-Shanghai High-Speed Railway, the Tianwan Nuclear Power Station in Jiangsu, the Hong Kong-Zhuhai-Macao Bridge, the South-to-North Water Diversion Project, and other major national projects, as well as overseas projects such as the Karachi Nuclear Power Plant in Pakistan, the Padma Bridge in Bangladesh, and the Vaca Hydropower Station in Belize.
Cement concrete is a man-made material with enormous usage and a wide range of applications. In Miao Changwen's view, trends such as digitalization, informatization, and intelligentization will "reshape" the performance of concrete materials.
"Entering the era of big data, with the help of technologies such as artificial intelligence and big data, we can design the internal structure of concrete. Recently, we have also been researching how to use artificial intelligence technology to extend the service life of concrete materials and save energy and reduce emissions," Miao Changwen said in an interview with a reporter from Science and Technology Daily. At present, the design service life of concrete materials used in major projects is 100-120 years, and they hope to use artificial intelligence technology to extend the design life of concrete to 200 years.
Some technologies have reached the international "leading" level
Reporter: Concrete is an important basic building material. At present, what level is China's building materials development at internationally?
Miao Changwen: Concrete materials are an important material foundation and carrier for major infrastructure. According to statistics, China produces 8-10 billion tons of concrete each year, accounting for more than 50% of global output, and has become the world's largest producer and user of infrastructure building materials.
At present, 85% of China's bridges use reinforced concrete, concrete and steel account for more than 90% of high-speed railways, and the vast majority of hydraulic engineering projects are concrete structures.
In terms of the applied basic theory and key technologies for high-performance concrete, China has reached the "running in parallel" level internationally, and some new materials and new technologies have reached the "leading" level internationally. China's research level and application achievements in concrete materials have reached a new level. Researchers have successively overcome international challenges such as shrinkage cracking of modern concrete, made breakthroughs in key technologies for ultra-high-performance concrete, established a long-life durability improvement system, and invented a new generation of polymer admixtures. The results have supported the construction of major national projects such as the Hong Kong-Zhuhai-Macao Bridge, the Baihetan Hydropower Station, the Shenzhen-Zhongshan Link, and the Tianwan Nuclear Power Station, playing an important role in ensuring a century-long service life of projects and helping nuclear power and high-speed railway technologies go global.
However, it should be noted that in terms of common basic theories and frontier engineering technologies for building materials, we still lag behind the international top level.
Reporter: You have led your team to provide support for the construction of more than 100 major national projects. In engineering construction of different eras and different functions, are there differences in the role played by concrete? How do you make adjustments according to different needs?
Miao Changwen: The construction of our country's major projects has strong regional, industry, and era attributes. These major projects span different eras and industries, but concrete application technology has played a crucial role in all of them.
During the construction of the Three Gorges Dam, the project faced the problem of temperature control for the massive-volume dam concrete. If temperature control is not done well, the dam will develop cracks. Facing the actual needs of the project, the team was stationed at the construction site and conducted repeated tests on the adaptability of the raw materials, mix proportions, and admixtures used, focusing on controlling the temperature rise caused by cement hydration in concrete. Ultimately, the relevant research results were applied to the third phase of the Three Gorges Dam project. At the same time, combined with temperature control during construction, it was ensured that no temperature cracks occurred after the dam was poured, further technically safeguarding the structural safety of the project.
The nuclear island concrete of nuclear power plants is a type of special concrete with the highest technical requirements, and its concrete admixtures had long been monopolized by foreign countries. We formed an innovative team with interdisciplinary collaboration between inorganic materials and organic chemistry, and reconstructed the admixture structure from the perspective of organic material molecules. After repeated tests, our results met the technical requirements of the project, achieved the first domestic production of admixtures in the nuclear island concrete of the Tianwan Nuclear Power Station, broke the foreign monopoly, and achieved progress in concrete admixture technology from "following" to "running in parallel."
During the construction of the Hong Kong-Zhuhai-Macao Bridge, the level of independent innovation in China's concrete engineering technology was comprehensively improved. For example, the immersed tube tunnel reaches a maximum water depth of 46 meters, which places higher requirements on the concrete for the immersed tube tunnel: on the one hand, the stability and uniformity of the concrete must be controlled, and the pumpability of the concrete must be maintained for several hours; on the other hand, the occurrence of shrinkage cracks in the concrete must be controlled.
Therefore, when designing concrete admixtures, the research team fully considered their synergistic adaptability with on-site raw materials and made adjustments in light of changes in the construction environment to meet the technical requirements of the project, contributing to the crack-free 6.6-kilometer immersed tube of the Hong Kong-Zhuhai-Macao Bridge.
At present, our team's technology has begun to be used in overseas projects, including major projects such as the Karachi Nuclear Power Plant in Pakistan, the Padma Bridge in Bangladesh, and the Jakarta-Bandung High-Speed Railway in Indonesia. We continue to promote the innovation and development of concrete admixtures and application technologies, and have also enhanced the international competitiveness of China's concrete admixtures.
Digital transformation boosts the development of building materials
Reporter: What are the development trends in the field of building materials, and what challenges does it face? What changes have technologies such as artificial intelligence and big data brought to the field of building materials?
Miao Changwen: Building materials with high strength and toughness, high durability, and green and low-carbon characteristics are key to supporting the safe, long-life, and sustainable use of major infrastructure. At present, strategic major engineering projects such as plateau railways and hydropower stations and cross-sea tunnels are being planned and constructed one after another. The number, breadth, and geographical scope of infrastructure construction are constantly expanding, and the operation and service of infrastructure are facing more complex loads, harsher environments, and more extreme application scenarios. All of these bring challenges to the development of building materials.
Digital transformation provides important support for the high-quality development of building materials. In recent years, artificial intelligence technology has emerged, and data-driven design combining multi-source information such as high-throughput computing, large databases, and machine learning has become an emerging path to break through traditional limitations and can enable reverse design of building materials guided by performance requirements. Technologies such as artificial intelligence and big data can effectively empower the low-carbon, green, and functional development of building materials.
In the future, such technologies will be applied more in the design, development, and application of building materials. Our team is also actively following up on related research work, establishing a large database of engineering materials and developing an intelligent material design platform to achieve high performance of engineering materials and ensure the application needs of major projects.
Reporter: Under the background of green and low-carbon development, what technological innovations do you think building materials should undertake to promote energy conservation and emission reduction across the industry?
Miao Changwen: Building materials are among the basic materials with the largest usage. The low-carbon, green, and sustainable development of building materials is the main direction for the future. However, current building materials have problems such as high carbon emissions, high energy consumption, and large resource consumption. Therefore, it is of great significance to use technological innovation to help achieve the carbon peak and carbon neutrality goals. Technological innovation work can be carried out in the following aspects.
First, reduce carbon at the source of materials, make full use of bulk industrial solid waste resources, develop new low-carbon cementitious systems, and reduce the amount of cement clinker used. Second, improve the mechanical and durability properties of concrete materials, increase structural bearing capacity, extend service life, and save the amount of concrete used under the same conditions. Third, develop new energy-saving, thermal insulation, and energy storage materials, such as cement aerogels and energy storage concrete, to reduce energy consumption and carbon emissions during the service life of buildings. Fourth, develop new, low-cost carbon capture, storage, and utilization technologies, such as full-oxygen combustion systems for cement and CO2 membrane absorption technology, to achieve carbon neutrality in the cement and concrete industry.
Reporter: Concrete cracking is a "killer" affecting building safety. In the 1980s, what stage was research in this field at? Why did you choose to engage in this research at that time, and what challenges did you encounter?
Miao Changwen: In the 1980s, research related to concrete crack control technology was still in its infancy, mainly reflected in the following aspects: concrete crack control theory was not yet mature, making cracking problems difficult to quantitatively evaluate; in addition, concrete, as a traditional material composed of cement, sand, and stone, had not yet introduced modern concrete performance control technologies such as mineral admixtures and chemical admixtures.
The problem of concrete cracking is a technical challenge urgently needing solution in the engineering field. At the same time, cracking also seriously affects the durability of structures and safety during service.
I chose this research direction, on the one hand, to meet the technical challenge, and more importantly, I hoped to contribute my own strength to safeguarding national engineering quality and benefiting society.
In the research process, we mainly faced challenges in two aspects. On the one hand, the causes of cracks are extremely complex, requiring interdisciplinary cooperation between materials science and structural engineering, while our team members were initially mainly inorganic materials experts and needed to break through this limitation through interdisciplinary integration. On the other hand, applying a new technology to major engineering projects often requires long-term technical reserves and experimental verification, which requires us to have the psychological preparation to seek truth from facts, sit on the "cold bench" for a long time, and continue carrying out research.
Fortunately, through our efforts, we have transformed the qualitative control of cracks in the past into quantitative calculation-based crack control now, truly achieving no cracking of concrete in underground tunnel projects, bridge projects, nuclear power projects, and mass concrete projects, turning the impossible into the possible.
Promoting the "two-way journey" between science and technology and industry
Reporter: You worked for many years at the Jiangsu Provincial Academy of Building Research and in enterprises, and moved to Southeast University more than ten years ago. Why did you make these career choices? Based on your experience, how do you understand the integration of technological innovation and industrial innovation?
Miao Changwen: After graduating from Nanjing Institute of Technology (the predecessor of Southeast University) in 1982, I entered the China Institute of Water Resources and Hydropower Research. Two years later, I went to work at the Jiangsu Provincial Academy of Building Research, where I eventually served as president of the academy. In 2002, Jiangsu promoted the restructuring of technology-development-oriented research institutions, and the Building Materials Research Institute of the Jiangsu Provincial Academy of Building Research was restructured from a public institution into a private enterprise, "Jiangsu Bote New Materials Co., Ltd." After the restructuring, the vitality of researchers was suddenly unleashed. Everyone worked hard to improve their capacity for technological innovation. In those years, while increasing efforts to research and develop concrete admixtures, we also extensively expanded the market, leveraging our talent and technological advantages, and within five years increased the company's output value by five or six times.
My grandfather was a private school teacher and my father was a teacher, so I had dreamed of becoming a teacher since childhood. In 2011, I accepted an invitation from Southeast University and joined the School of Materials Science and Engineering, finally realizing my childhood dream.
If working at the research institute and the enterprise meant thinking about how to discover problems from engineering and test the value of results in engineering, then entering a university to do research means explaining principles from the level of basic theory and from the perspective of material mechanism analysis, and then guiding engineering practice. My previous work experience at the research institute made me pay more attention to carrying out basic research from the application level and writing papers on the land of the motherland.
In recent years, we have also been trying to promote collaborative innovation in the materials industry, hoping to use technological innovation to drive industrial innovation. In the "Collaborative Innovation Center for Advanced Civil Engineering Materials," jointly established by Southeast University, Tongji University, Tsinghua University, and five other universities and five enterprises including China State Construction Engineering Corporation, universities and enterprises frequently exchange views on academic research directions and industry development trends. Sometimes enterprises provide research funding to universities for pilot and intermediate tests for achievement transformation; sometimes universities conduct theoretical research and quantitative analysis for enterprises' technology development. This cooperation model provides important support for tackling key common technologies in the industry and solving major basic problems constraining industry development.
Reporter: At present, in order to further stimulate the innovation enthusiasm of researchers, China encourages researchers to innovate and start businesses and promotes the transformation of scientific and technological achievements. What do you think about this?
Miao Changwen: We should not be afraid to push researchers into the sea of industry to swim, and we must tolerate failure. Even if a few projects "drown," it does not matter; we should encourage researchers to courageously carry out the transformation of scientific and technological achievements and apply them to industrial development as soon as possible. At the same time, researchers should be allocated a reasonable share of the returns from achievements, incentive policies for the transformation of scientific and technological achievements should be improved, the enthusiasm of researchers for innovation and entrepreneurship should be stimulated, and the deep integration of science and technology with the economy should be promoted. For young researchers, we should be good at guiding them, giving them responsibilities, and strengthening their courage, and let them boldly explore.
[To young scientific and technological talents]
Young scientific and technological talents should have ideas, be loyal to their cause, and be capable and willing to work hard.
Materials research involves many fields closely related to people's lives, such as transportation, buildings, and water conservancy and hydropower facilities. Young scientific and technological talents should closely follow the needs of national and industry development, refine research directions, empower China's construction with technological innovation, build safe, comfortable, green, and smart good houses, and meet the people's demand for high-quality housing.
Young scientific and technological talents should have a sense of homeland and a spiritual pursuit like "the spring silkworm spins silk until death, and the candle weeps tears until it turns to ashes," and should also have the acumen to discover problems and the professional quality to solve them, striving tirelessly to achieve high-level scientific and technological self-reliance and self-strengthening.
— Miao Changwen
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