new water-repellant concrete impregnated with tiny superstrong fibers promises to leave roads and bridges free of major cracks for up to 120 years. University of Wisconsin-Milwaukee civil engineers have developed a concrete mix that is durable and superhydrophobic. They call it Superhydrophobic Engineered Cementitious Composite (SECC). Preventing normally porous concrete from absorbing water means that liquid can’t get inside, freeze and cause it to crack. The concrete’s unusual characteristics, including being significantly more ductile than traditional concrete, means that cracks that do form do not propagate and cause failure. “Our architecture allows the material to withstand four times the compression...