Methods and apparatus for continuously extruding a hydraulically settable mixture and simultaneously placing continuous filaments within the extruding mixture to yield articles having a filament-reinforced, hydraulically settable matrix. The filaments can be placed within the mixtures in a parallel configuration, a helical configuration, or combinations thereof, in order to yield an article having the desired properties of, e.g., tensile strength, flexural strength, hoop strength, burst strength, toughness, and elongation ability. The desired properties of the hydraulically settable mixture, as well as of the cured hydraulically settable matrix of the hardened article, may also be adjusted by including varying amounts and types of aggregates, discontinuous fibers, binders, rheology-modifying agents, dispersants, or other admixtures within the hydraulically settable mixture. Optimizing the particle packing density while including a deficiency of water yields a hydraulically settable mixture which will flow when an extrusion pressure is applied but be form stable upon being extruded.