innovative materials

The built environment currently consumes 51% of total U.S. energy of which 39% is consumed by the operation of buildings (primarily in heating and cooling) and 12% is consumed by construction material fabrication and demolition. The built environment also contributes to 55% of total U.S. CO2 output of which 43% is the result of energy production for building operation and 12% is again in material fabrication and demolition. At Stanford, one way that we are seeking to lessen the negative impact our built environment has on our natural environment is through research on innovative, sustainable building materials.

We are developing new construction materials, as well as re-engineering current materials, that are cement-based, polymer-based, and bio-based. Our research is cross-disciplinary with collaborations among civil, environmental, chemical and material science engineers. Current materials research in our department includes the development and evaluation of fiber-reinforced polymeric materials that are made from renewable resources such as biobased polymers and natural plant fibers. Advantages of such materials include a reduced dependence on nonrenewable energy sources for material production and reduction of recalcitrant, non-degrading construction & demolition debris in landfills. The ability of these materials to replace various non-structural and structural materials in buildings, to avoid deterioration while in-service, and to biodegrade after their useful service life is currently being investigated. Computational models and theoretical developments are underway to predict the performance of these highly nonlinear materials. In the area of improved building energy-efficiency in building operations, we are investigating new green insulating materials in structural panels.

Additional research is being conducted on re-engineering existing materials for improved performance and sustainability, including the application of fiber reinforced polymer composites and high-performance fiber-reinforced cement-based composites, such as Engineered Cementitious Composites (ECC) that exhibit very fine, multiple cracking and tensile strain hardening up to strains of 3%. These materials, commonly called “bendable concrete” in the mainstream media, are highly damage-tolerant in both tension and compression and have potential for improved durability against corrosion as well as resistance to overloads such as earthquakes with minimal damage. The application of these materials to new, sustainable building and infrastructure designs, as well as to structures needing seismic retrofit is being investigated through physical experiments and computer modeling, including performance-based assessments.