Strand - a single wire or group of bundled wires. In post-tensioned construction a strand is a unit of post-tensioning reinforcement, similar to a reinforcing bar being the unit of RC reinforcement.
Duct - a tube, conduit, or sheathing containing one or more strands with a single anchorage. The maximum number of strands in a duct is defined in the prestressing material properties. For monostrand tendons (bonded or unbonded), each duct contains a single strand.
Tendon - In practice, the PT industry defines a tendon as a group of strands that share a common anchorage. The "group" may be just one strand, as is the case with most unbonded systems, or "monostrand". It is not always necessary for real tendons to match RAM Concept tendon exactly. For example, it is common practice in monostrand to group tendons together in the field. For this situation, it is usually convenient to specify the total number of strands in the group in a single RAM Concept tendon. In this case the correct number of ducts can still be calculated correctly using the input duct properties.
