Some 2,000 delegates from more than 40 countries attended the Fifth International Prestressed Concrete Conference in Paris last year. From the mass of their written and verbal discussion several trends emerge which are of practical importance to builders and designers. More and more designers are thinking in immediate terms of prestressed concrete construction. Segmental construction, using precast elements, joined by post-tensioning, offers major savings. The use of very large units in increasing. Smaller units are usually located on falsework to serve as permanent forms, after which a concrete cap is placed over them to make the whole section continuously monolithic. Joints between unties are frequently made with epoxies. Almost all the outstanding structures reported to the congress showed this precast/ epoxy trend. The crack free nature of prestressed concrete is boosting exploitation of the material for all types of liquid retaining and transporting structures. Pipelines are being post-tensioned in lengths up to 1,500 feet in New Zealand. In Austria, post-tensioning is being used to raise the height of existing dams by tying new concrete to old to give a watertight monolith. In Tasmania, a hydroelectric dam has been prestressed in its entirety, including the spiral casing of draft tubes. Machinery structures provide the newest field of application for prestressed concrete. Typical installations include motor test frames, forge hammers, rocket test stands, strip mill bases, turbine supports, and rolling, polishing, and grinding machines. Conventional machinery comprises three main structural elements- the frame of the machine, its base and a foundation. Prestressed concrete allows two or all of these to be combined. Cost savings between 50 to 90 percent have been achieved in Britain and Russia.