concrete

  • cement alternative
    April 13, 2015  

    Cement has been called the foundation of modern civilization, the stuff of highways, bridges, sidewalks and buildings of all sizes. But its production comes with a huge carbon footprint. Environmental chemist David Stone was seeking a way to keep iron from rusting when he stumbled upon a possible substitute that requires significantly less energy. Special correspondent Kathleen McCleery reports. Continue reading

  • September 17, 2008  

    Thirteen months after a bridge collapse killed 13 people in Minnesota, a new 10-lane structure reopens to traffic Thursday morning. Fred de Sam Lazaro reports on the engineering behind the I-35W’s multi-million-dollar reconstruction. Continue reading