Civil engineering infrastructures include concrete structures (e.g., buildings, dams, bridges, waste treatment plants, waste disposal sites, and nuclear power plants) whose long-term performance and function are critical. The deterioration of these structures with time increases maintainance costs and adversely impacts their operating conditions and increases the risk to public safety. Concrete degradation is one of the most important problems faced by civil infrastructure (ASCE, 2009) and is a large burden on the US economy. Conventional cement-based materials suffer from numerous deficiencies such as lack of ductility, low tensile strength, poor impact resistance, low electrical conductivity, and concerns over long-term durability.

The National Academy of Engineering identified “restoration and improvement of urban infrastructure” as one of 14 Grand Challenges for Engineering in the 21st Century (National Academy of Engineering, 2008).

Our research is addressing this challenge by elucidating the complex processes associated with cement-based composites and the relationship between molecular level chemical changes at internal interfaces and the macro-scale properties affected by those changes and by the development of novel, cement-based composites with superior structural and functional properties and enhanced long-term durability. The emphasis is on developing new knowledge of the chemical mechanisms and interactions at interfaces and then scaling this knowledge of interfacial processes to engineering properties.

Our research effort comprises three aspects:

• Nano-engineering and multiscale performance of cement-based composites
• Molecular scale interface engineering of hybrid calcium-based composites
• Multiscale durability of nano/microfiber reinforced cement-based composites