Per Jahren is semi-retired and has in later years concentrated most of his time on writing. He has written more than 150 papers, articles, and books on concrete, and given lectures on concrete subjects, and concrete and sustainability. He received a master’s degree in civil engineering, from the Norwegian Technical University, and is a former chairman, and honorary member of the Norwegian Concrete Society. Since 1986, he has been involved in his own company, P.J. Consult AS. Per Jahren became interested in environmental issues in the cement and concrete industry in his career and gave his first paper on the topic over thirty years ago. Sui Tongbo , is the founder and director general of Sinoma Research Institute and vice president of China Sinoma International Engineering Co. Ltd. As a professor, his focus is in the R&D of low energy and low CO2 emission cements. Before joining Sinoma International, he was engaged in the R&D of special cements and new cementitious materials at China Building Materials Academy (CBMA). Dr. Tongbo graduated from the Department of Applied Chemistry in the Shandong Building Materials Institute with a BS degree, and from the Department of Inorganic Materials Science and Engineering in the China Building Materials Academy with an MS and PhD degree.