In tunnel lining, time and safety are the two most important parameters. The use of KraTos™ Macro reinforced concrete lining provides ductility and prevents sudden collapse. KraTos™ Macro eliminates steel reinforcement application and saves time to the tunnel construction project. Exposed to groundwater, steel reinforcement might incur sectional loss due to several reactions. Therefore, reinforcement that is resistant to corrosion extends the service life of concrete. Fire resistance is the most important safety concern in any tunnel construction. As KraTos™ Macro synthetic fibers have no thermal conductivity, they do not contribute to the heating of cement as steel wires or other reinforcements would do in case of fire. Similar to other polypropylene fibers, KraTos™ Macro has a high melting temperature, which helps to preserve the structural integrity of the tunnel lining after a fire.