A precast concrete floor panel having stems molded in a mold with stem mold cavities and a deck. The deck can be formed in the same mold that includes the stem mold cavities or the concrete for the deck can be poured and cured on-site after the stems have been removed from the mold. The mold can include mold segments made from an insulating material that can remain attached to the stems to insulate the finished floor panel.

A structural assembly (20) providing both a surface (21) and an insulating stratum associated with the surface. The assembly (20) can comprise structural members (23-24) and pods (30) associated with the structural members (23-24). The pods (30) contribute to structural integrity, thermal insulation, and/or sound attenuation. The pods or pod-like material can be used in or on horizontal or vertical cavities, in or on horizontal or vertical surfaces, and/or incorporated into a structural assembly or equipment housing.

A bridge system is provided that utilizes foundation structures that are formed of the combination of precast and cast-in-place concrete. A method of constructing the combination precast and cast-in-place concrete foundation structures involves receiving at a construction site a precast concrete foundation unit having elongated upright wall members that define a channel therebetween, and multiple upright supports located within the channel; placing the precast concrete foundation unit at a desired use location; delivering concrete into the channel while the precast concrete foundation unit remains at the desired use location; and allowing the concrete to cure-in-place such that the elongated upright wall members are connected to the cured-in-place concrete by reinforcement embedded within both the cured-in-place concrete and the upright wall members. The bridge units may be placed before the pouring step to embed the bottoms of the bridge units in the cast-in-place concrete.