Axial shortening

• Chris Oregan ^[1]
  1. [1] Albert Einstein College of Medicine

     Albert Einstein College of Medicine

     Estados Unidos

     
• Localización: The Structural Engineer: journal of the Institution of Structural Engineer, ISSN 1466-5123, Vol. 99, Nº. 1, 2021, págs. 24-28
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • Until the late 19th century, the tallest buildings in the world were religious structures, whose spires and domes pierced the sky. This changed in 1885, with the erection of the Home Insurance Building – the world’s fi rst tower block – in Chicago. Framed in structural steel, it stood 42m high with 10 storeys of offi ce space.

    The new technology demonstrated in Chicago caught on in cities across the world and the Home Insurance Building was quickly dwarfed by subsequent structures as the race to the sky began. However, it brought with it a signifi cant concern: the vertical movement of vertical loadbearing elements in multistorey structures.

    This Technical Guidance Note concerns the concept of axial shortening – a phenomenon that occurs in vertical loadbearing elements within all structures, but whose eɈ ects are especially pronounced in those over 15–20 storeys high.

    Reinforced concrete frames are most prone to axial shortening due to the impact of shrinkage and creep on composite materials.

    This note covers the causes of axial shortening, how it is assessed and predicted, and the mitigation measures structural engineers and building contractors employ to counter its eɈ ects, particularly in relation to fi t-out and facade installation following building construction.

    The note also refers to ways in which current codes of practice oɈ er a means to analyse structures for axial shrinkage.