Abstract: An elongated concrete structure, such as a bridge, is constructed by providing at a construction zone located at one end of the site of the structure a formwork arrangement which includes a bottom formwork within which the structure may be formed in discrete sections. Successive discrete sections formed in the formwork are joined together and launched in series from the construction zone toward the opposite end of the site across which the structure is to extend. As each section of the structure is launched, the bottom formwork is moved together with each section across one section length in the launching direction while the remainder of the formwork arrangement is maintained stationary at the construction zone.