Abstract: This invention relates to a method for making concrete conduit. The method of this invention pertains to forming a conduit mat of material on a form, advancing the formed conduit mat of material from the form, fastening the conduit mat together, cutting the conduit into desired lengths, applying concrete on the conduit mat, working the concrete from both the inside and outside of the conduit mat to form smooth surfaces on both surfaces of the concreted conduit mat and curing the concreted conduit mat to form concrete conduit. In one embodiment of this invention, the method is performed from a mobile base which moves forward as the concrete conduit is continuously made and layed on the ground or underwater.

Abstract: This invention relates to an apparatus for making concrete conduit.The apparatus of this invention for making concrete conduit comprises a base and a transmission mounted on the base with a power unit drivingly connected to the transmission; a form connected to the transmission for shaping a conduit mat of material; feeders drivingly connected to the transmission for applying material over the form to form a conduit mat of the material; advancing apparatus to move the formed conduit mat from the form; fastener apparatus for binding the layers of conduit mat together as the conduit mat is advanced; injection apparatus connected to the base for injecting concrete on the conduit mat; trowel means adjacent the inside and the outside of the conduit mat for working the concrete into the conduit mat and smoothing both the inside and the outside surfaces of the conduit mat; and means for controlling the curing of the concrete conduit thus formed.