Construction and Structural Repair Solutions - DSI USA From the steel in our first reinforced bridge in 1903, to today’s infrastructure intelligence, we’re extending the lifespan of the world’s structures Post-Tensioning and Geotechnical Systems You can Rely on: DYWIDAG-Systems International USA for Construction Solutions. Our company, DYWIDAG-Systems International USA Inc., is part of the international DSI Group. DSI’s scope of business is the development and application of Post-Tensioning and Geotechnical Systems.