Design agencies and regulations Worldwide, many professional organizations exist to promote best practices in the design and construction of prestressed concrete structures. In the United States, such organizations include the Post-Tensioning Institute (PTI) and the Precast/Prestressed Concrete Institute (PCI). Similar bodies include the Canadian Precast/Prestressed Concrete Institute (CPCI), the UK's Post-Tensioning Association, the Post Tensioning Institute of Australia and the South African Post Tensioning Association. Europe has similar country-based associations and institutions. It is important to note that these organizations are not the authorities of building codes or standards, but rather exist to promote the understanding and development of prestressed concrete design, codes and best practices. Rules and requirements for the detailing of reinforcement and prestressing tendons are specified by individual national codes and standards such as: European Standard EN 1992-2:2005 – Eurocode 2: Design of Concrete Structures; US Standard ACI318: Building Code Requirements for Reinforced Concrete; and Australian Standard AS 3600-2009: Concrete Structures. See also References External links The story of prestressed concrete from 1930 to 1945: A step towards the European Union Guidelines for Sampling, Assessing, and Restoring Defective Grout in Prestressed Concrete Bridge Post-Tensioning Ducts Federal Highway Administration Historical Patents and the Evolution of Twentieth Century Architectural Construction with Reinforced and Pre-stressed Concrete Building materials Concrete buildings and structures Reinforced concrete Structural engineering fr:Béton#Béton précontraint sv:Armerad betong#Spännarmerad betong