Abstract: The present invention is directed to improved tank or containment vessels and processes and apparatus for their construction. The tanks or containment vessels usually consist of circular walls resting on a base and a dome supported by the walls. The dome of the subject prestressed tank is formed by deploying or creating a membrane on the base, applying one or more layers of rigidifying material (and prestressing or reinforcing material if needed) on the membrane and then forming said membrane into a dome before the rigidifying material sets by the selective introduction of compressed air at appropriate locations between the base and the membrane. The hardening of the rigidifying material results in a composite preformed rigid roof or dome having a membrane liner and an overlay of composite construction. Once the walls are created, air pressure can be further utilized to raise this preformed composite dome upward to a predetermined height after which it is fastened to the walls.

Abstract: The present invention is directed to improved tank or containment vessels and processes and apparatus for their construction. The tanks or containment vessels usually consist of circular walls resting on a base and a dome supported by the walls. The dome of the subject prestressed tank is formed by deploying or creating a membrane on the base, applying one or more layers of rigidifying material (and prestressing or reinforcing material if needed) on the membrane and then forming said membrane into a dome before the rigidifying material sets by the selective introduction of compressed air at appropriate locations between the base and the membrane. The hardening of the rigidifying material results in a composite preformed rigid roof or dome having a membrane liner and an overlay of composite construction. Once the walls are created, air pressure can be further utilized to raise this preformed composite dome upward to a predetermined height after which it is fastened to the walls.

Abstract: A permanent recording is made of the force applied to a prestressing element such as a steel cable as well as its resulting elongation in the process of taking up its slack and in subsequently tensioning and locking off the cable in its final stressed condition, such recording being particularly useful in establishing actual values of stress and strain along a cable length inside of a tube which is in frictional engagement with the cable.

Abstract: A permanent recording is made of the force applied to a prestressing element such as a steel cable as well as its resulting elongation in the process of taking up its slack and in subsequently tensioning and locking off the cable in its final stressed condition, such recording being particularly useful in establishing actual values of stress and strain along a cable length inside of a tube which is in frictional engagement with the cable.

Abstract: An adjustable coupler is on opposite ends of a cable for securing a pre-established tension in the cable. Such pre-adjusted tension is effected by conventional tensioning mechanism applied between a pair of nuts threaded on opposite ends of the cable. The coupler itself involves an elongated turnable coupling body which spans ends of the cable and in which a first nut is threaded in one of its ends and a second nut is threaded in its other end. The first nut is engageable with abutment means on one of the cable ends inside of the coupling unit. The second nut is threaded on both the cable and in the coupling body and is secured to the coupling body such that turning of the coupling body results in its movement about the axis of the cable to cause the first nut to engage the abutment means at which time the coupler is then adjusted to maintain the pre-adjusted tension. Thereafter the tensioning mechanism may be removed.