Marble, a nontraditional cladding material for high-rise structures, has been treated primarily as a design issue by architects. During recent years, improvements in the cutting process have allowed the thickness of the cladding panels to decrease markedly. This has led to a dramatic increase in the use of this form of cladding. It has also led to recent nation- wide problems with marble cladding on buildings that are no more than twenty years old. The observed problems of the marble cladding include severe and permanent bowing of the material that starts soon after the buildings are completed, and the eventual failure of some of all anchorages of the cladding to the building. In addition to disastrous economic consequences for the building owners and the marble and curtain wall industries, there are potential risks to life associated with high-rise construction that may be dangerously increased in the future. There is a controversy among experts about the cause of the permanent bowing and the effect of the restraints provided by the anchorages. This research will investigate the alleged causes of permanent deformation, thru-thickness temperature differentials and moisture. The results of the research will include recommendations for building code specifications for an engineered solution to the marble cladding reliability problem, as well as the development of an ASTM Standard for Subcommittee E6.55 on the Performance of Exterior Building Wall Systems.
