Millennium arch

Abstract

The masonry arch has been the most characteristic element of architecture and engineering ever since the Romans elaborated on the original Etruscan form, surpassing Hellenic culture in this regard.
Since then, the arch has been used as an efficient construction solution for spanning spaces with materials unable to resist tensile stress. The technical originality of the arch was such that even in modern times it has been used to symbolize feats of war: hence the arches of triumph to be found throughout the western world.
The turn of the century and millennium ushered in a technical breakthrough that was introduced in this Congress: AllWall. This system enlarges the potential of masonry by devising a way to reinforce hollow brick or block walls with steel in all three dimensions of space.
The Millennium Arch, built to commemorate the 12th IBMAC held in Madrid, exhibited the technical advances inherent in AllWall: this slanted arch was the first masonry structure of its kind to be built off the vertical, using “Ladriflor” brick in a header bond arrangement, reinforced with bars and stirrups.
Designed by J.M. Adell (President of the 12th IBMAC), the arch consisted in a 14-m diameter cylinder on a 30º slant, made of a one-foot deep masonry wall, with one course of yellow for every six courses of red brick. It spanned a width of 10 m and a height of 5.5 m. The wall was uniformly reinforced with truss bar across every sixth bed joint. The arch area (structurally, a curved and cantilevered beam) was reinforced with 10-mm diameter longitudinal bars and stirrups that penetrated the laterally accessed perforations in the standard hollow brick.
The Millennium Arch was built on the grounds of the Palacio de Congresos, the convention centre located on Madrid’s main thoroughfare, the Paseo de la Castellana. Two years later, the centre’s new management obliged the municipal authorities to demolish the arch.
The photographs below portray the most significant stages in the erection of the Millennium Arch outside the Palacio de Congresos, venue for the 12th IBMAC.
These pictures are divided into six chapters: Background, Components, Springline, Piers, Arch, Centring Erection and Removal, and Trimming.