One World Trade Center (1WTC) is scheduled to open in late 2013. To date, most of the concrete has gone into the structure’s monolithic pedestal designed to protect against below- or above-grade bomb attack. The reinforced concrete core walls will protect stairwells that are 20% wider than mandated by the building code. They will be also pressurized to prevent smoke from hindering possible evacuation. The building will include advanced energy conservation technology, next generation glass, and high-efficiency systems to reduce energy and water consumption

Tensile behavior of ultra-high performance fiber-reinforced concrete (UHP-FRC) was optimized by improving the matrix packing density, using very high strength fine diameter steel fibers, and tailoring the fiber-to-matrix interface bond properties. The developed UHP-FRC mixtures achieved record high tensile strengths, up to 37 MPa (5.36 ksi). The energy absorption capacity up to peak stress was about an order of magnitude higher than the values reported by other researchers. The results imply that the new material has the potential to be particularly useful for structures subjected to blast, impact or seismic loading

Using CO2 of 99% purity to simulate CO2 recovered from cement kiln flue gas, early-age CO2 curing of dry-mix, lightweight, and normalweight concrete mixtures was evaluated. Specimens prepared in the laboratory were evaluated for carbon uptake, strength gain, pH, and chemical analysis. Manufactured concrete pavers were evaluated for durability. The authors believe that early-age carbonation curing can provide permanent carbon storage and improve short-term and long-term performance of concrete